You asked for specifics so here is mine. I volunteered in a large primary, studied for extra qualifications (SEND) so was basically treated as a TA/LSA as much as possible.
The upsides, most of the children are just lovely, it is rewarding when they grasp something they struggled with, seeing them progress both academically, socially and they are pretty funny too. The teachers are trying their best to engage the children.
The downsides, you can be treated as a general dogsbody. As a volunteer I wasn't put in classrooms with violent children. I didn't have "Team Teach" training, ie de-escalating dysregulated children and so didn't have to manhandle a child from a classroom. I was never injured as a result. Teachers and TAs have been spat at, kicked, hit, fingers broken, lesser stuff sworn at, name called and the language is shocking. This is an outstanding primary in a lovely area but some children have never been told no by a parent and some have horrific home lives where it is considered safer to be in school than at home.
There will be "rainbow rooms" or places to put angry, stressed children who need time to calm down in a safe environment. This is in lots of schools. So a child screaming let me out you fuckers, I will fucking do you from the mouth of a 6 year old was normal. As a TA you will probably have a shorter lunch (long term TAs had an hour, new staff had 30 minutes) the other 30 minutes were 1 to 1 duties keeping an eye on children who have a 1 to 1 in the classroom and that TA needs their lunch break.
I did have full safeguarding training before being in the school, had to sign and read certain school policies especially first aid and confidentiality. Did I love it? Yes I absolutely did. Would I choose the admin job? Yes.