The best advice I can give is try to volunteer in a school first to experience it firsthand and work out if it is for you. You will need a DBS check and some schools have a volunteer training program that covers safeguarding, policies, and some basic children stuff.
A lot of TAs now have 1 to 1 caring duties whether that is in a classroom or over lunch to give another 1 to 1 TA their lunch break, this could be sitting with a child whilst they eat to following them around the playground.
Even in the best schools there are still children with behaviour issues. You may have to be trained to safely remove a child from a classroom, you may get injured too.
Depending on the school depends on the duties which can be anything from gluing worksheet homework into books, cutting out things for the display boards, reading with the children, helping low ability children with the practical side of subjects like science or art. It can also be standing at the photocopier for 40 minutes. This is as well as supporting the teacher in the classroom.
That is the reality but it is also incredibly rewarding and fun, each day is different and the topics the children cover are interesting too. Most teachers are great and everyone is trying their best for the children with limited budget for things like whiteboard pens and pencils.
You get a lot of holiday and if the school holidays align with your child's school holidays then you won't have to pay for childcare in the holidays. How are you getting your children to school? Partner or are you planning on being a TA in your child's school? It will depend on your start time and what time the doors open for your children to go into school. TAs were not allowed to bring their children into school before school doors opened, one did this and it caused kick off from the parents in the playground, they had to pay for wrap around care.
You are not full time so still have time after school finishes when most people are still in work. That is the pay off. The money, not so great but you can train to be a HLTA or take on extra duties.