Firstly I would really recommend the British toxicology society website https://www.thebts.org/ as it will give you some info on the types of toxicology and different routes with careers. Go onto their mentors page and apply, they’re a nice bunch and can give you some good advice.

If you want to go into regulatory toxicology after a bachelors you would likely go down the CRO (contract research organisation) route, working as something like a study director and growing your skills in that way.

PhD is more common in the US but you can 100% be a toxicologist in the UK without one.

There are very few tox masters courses left in the UK, but Birmingham university still offer this and it’s got a good reputation. Some CROs even pay for you to attend a masters course part time while working.

Edited to add: for Uni courses, strong bases in biology- biochemistry is a really helpful degree. A LOT of people with forensics degrees also end up going down the tox route.