Hello, I'll get the ball rolling and maybe chip in. Disclaimer, all my experience pretty much is in various parts of public sector HR, things may be different elsewhere particularly in roles with an international/global company.
how is the workload / stress levels for you? Do you frequently have to work late to get tasks done?
I've pretty much always found it fine, I've worked in generalist roles as well as specialist ER/change management/TUPE/strategy/project jobs and like with anything, there are stressful/difficult parts and easier/more boring bits. Expecting any job to be 0 stress is not realistic but I've always found it perfectly manageable. The parts I have found stressful are probably also the sorts of things that are difficult in any (corporate) role, various flavours of bad boss/difficult colleagues/poor workplace culture rather than anything specific to HR, but then again I don't find the parts of HR that (some) others dislike/find difficult such as dealing with upset people or redundancies or employment tribunals particularly stressful per se, challenging perhaps and occasionally emotionally draining (I am a trained mediator and those are always very intense days). But others would maybe find that really challenging and it would play on their minds a lot - on the other hand I deliberately avoid the more OD/learning and development side of HR as it's not really my thing so maybe my answer would be different if I worked in that specialty, I'd really recommend doing some work experience in HR if you can even just shadowing, as often it's not what people expect from a job (a lot less dispensing tea and sympathy and a lot more admin than people expect is the common theme!) before making the plunge of a career switch, and this will help give you an idea what kind of role in HR you'd like best too.
Working hours wise it's also usually fine, pretty much a consistent 40ish hour week, I do occasionally work late currently but not that often and not excessively late when I do. When I was starting out perhaps I did a bit more evenings/weekends (particularly when I was studying alongside work) but not a lot, and probably I could have got away with less, I was just a keen bean in those days (which are long gone, lol!). I'd say 40 hours per week is fairly standard for public sector HR, plenty of people work flexibly or part time to some degree also. I used to have a job which involved a lot of (UK) travel as I covered a wide patch and regular site visits were an expectation so that added a lot of hours but a lot of that has changed since Covid and remote working much more common/feasible now. I think I've pulled 18 hour+ days only a handful of times ever, once when we managed to delete an entire payrun on the eve of payment back in pre-digital days and it was all hands to the pump to manually recreate it, and a couple of times related to deadlines for major change programmes or tribunals or something, but I could honestly count those times on one hand in a 20 year career.
What kind of role would you recommend for a new starter going into HR who prioritises work life balance?
Public sector HR! The pay is worse than private but I'm sure the work life balance will be better. Classic new entry to public sector HR roles would be HR administrator or recruitment administrator, pretty poor pay and not truly a graduate role (although most people doing them are graduates and many have CIPD already) but you might be able to get one of these without your CIPD and then you should be able to get it once in post (if you are really lucky the company will contribute to the fees and/or give you some time off for study) - from there you should be able to progress to HR advisor or L&D administrator and into L&D management if that's your preference. Or the alternative would be apply for one of the public sector HR graduate training schemes, the NHS one in particular is excellent albeit very competitive, then you'll get all your training both qualifications and on the job in one place (there may be higher expectations on your hours whilst on a training scheme but you should then be able to settle into a manageable role).
what does your day to day look like?
Varied - lots of email correspondence, meetings, phone calls. I manage a team now so a large part of my day is supervising, chatting to, generally looking after them. I tend to flit about between scheduled meetings, crisis management/coaching managers through difficult situations, trouble shooting, and fitting in more strategic work like policy reviews, workforce planning, improvement projects. You have to be comfortable with this style of working in a lot of HR jobs (there are some that are purely scheduled/non urgent work but mostly a mixture of stuff that crops up day to day and longer term things).
generally, are you happy? What do you like and dislike about working in HR?
Yes I'd say I'm happy. It's not the kind of job IMO that gets you out of bed singing in the morning (few corporate jobs are!) but I feel it (a) serves a useful function, when done well makes the organisation work better and because it's public sector, therefore makes society better (b) has it's interesting, fulfilling and challenging (in a good way) parts and (c) pays reasonably well once you reach a relatively senior level whilst not overtaking your whole life, facilitates a nice lifestyle. I won't pretend it's all (b) and no boring drudge work or pointless meetings or frustrations because that would be a lie, of course there are parts of the job I'd rather avoid but on the whole the good outweighs the bad. My major dislike is actually the general perception of HR, in the media and many people's minds we're either pointless fluffy hug-dispensing and wokery-spouting simpletons who are entirely lacking in enough business/common sense to do a 'real job' OR clipboard toting bureaucratic peons enforcing pointless corporate rules and/or wantonly sacking people left right and centre on some kind of sad power trip. The real frustration is when you occasionally come across a fellow HR professional who fulfills one of the stereotypes 
!
Good luck, happy to answer any questions you may have!