Try to volunteer first because the realities of the job are sometimes different from what you think they might be. I have volunteered in a primary for almost a decade. I do it because I love it and I don't need to work luckily.
First I had to undergo a volunteering in school course provided by the school, mainly covering things like safeguarding and disclosure, policies (first aid being a huge one) then confidentiality/professionalism, reading with some children so they can see your interaction skills.
I do have a degree and maths and English GCSEs. Both my children attended the school so I was already known by some staff as I started when Ds2 started reception.
LSAs (Learning Support Assistants, the new name for our TAs) are often asked to be cover supervisors so basically a teacher for non-core subjects so PE, geography, tech etc. There is an increase in pay of about £1 per hour so a couple of quid a day. The take home pay for LSAs is paltry but the benefits are no childcare costs.
Once you are in a school you can see that LSAs have little responsibility outside of the classroom and can leave at the end of a school day, teacher's days are much longer, often starting before 8 and ending after 5 or 6.
Responsibilities vary from, generally supporting learning within the classroom, doing intervention work with small groups or 1 to 1, display boards, photocopying, trimming sheets so they fit into their books etc. School trips both day trips and 1-2 night residential trips means you probably won't even make minimum wage as you'll work through your unpaid lunch and possibly before or after the normal start time.
But, I keep doing it because I love it. The school are fantastic, the staff are wonderful and go above and beyond for the children, and the children are fab.