Young trainee teacher confused about copyright: can I use books/e-books that I purchased for my lessons or is it a copyright violation?

I'm an English trainee teacher from Europe and I'd like to read some books with my students. I know most teachers don't really pay attention to this stuff but I'd like to know how to do this legally for most of the books have a disclaimer that they can't be used outside personal use or that they 'cannot be transmitted in any for or by any means'. Obviously, I don't plan copying the whole book and posting it for the whole class to access. How to do it correctly?

I know the question may seem super stupid to you but, as I've already written, I'm just a trainee, and we weren't taught it during our classes.