My two are 18 months apart. Their dad fucked off in my final month of pregnancy with the second so that added an extra level of fun to the proceedings but thankfully I had my parents around a lot to help out.
I honestly didn't find the first six months bad at all. Everyone was being very gloomy in their predictions and 'ooooh you'll have your work cut out for you' but it was great. I do have a lot of experience with babies and small children though so that may have helped.
Positives were that older child was still so little there wasn't any jealousy. After about a week or so he didn't really remember being an only child so just kind of accepted baby being there!
Toddler was given a box of toys that came out at feeding time (I breastfed on demand so this happened a lot) and only feeding time so they stayed exciting and kept him occupied. Failing that CBeebies is your friend. Lower your expectations re screen time limits and then lower them again. Also books can be read to toddler while breastfeeding baby, just takes working out the right hold!
Once again, lower expectations and standards. Sometimes everyone will be dressed and you'll manage a day out to a national trust and picnic, other days there'll be no point getting dressed before everyone has to be back in pyjamas again! This is ok
Babies can be endlessly fascinating to toddlers. Don't leave them alone together! Equally, the baby may not be as interesting as you think they're going to be. Doesn't mean they're not going to love one another, just means toddlers are fickle.
You absolutely will love the new baby. It might take a while, it might be instant but it will happen. I found with my second baby I fell in love instantly (as I did with my first) but I was very very aware I didn't know him. My oldest child by then was such a distinct personality with likes and dislikes and sense of humour etc and suddenly here was this tiny person who I loved so much but I didn't know at all. It was weird!
You'll middle along and work things out and get things right and make mistakes just like you did your first. Get a sling. Slings are so much more helpful for second babies when toddler wrangling!
The one thing I could never work out was bath time. Baby was too slippery and fragile initially to go in the bath with toddler but always ALWAYS geared up for a massive cluster feed whenever I put toddler in bath (no matter how much I varied the time), toddler couldn't get in and out of the bath without my help but I had a baby attached to my boob, then I needed to try and dry and put nappy on toddler one handed.....it became a lot easier once the baby was solid enough to go in the bath with his brother!
Other than that enjoy! I loved those days and would happily go back to them ❤️