Bots are Telegram users that you interact with using commands to control it. A bot can see your public username and profile pictures. They can also see the messages you send to them but nothing else from other chats, channels, etc.

Bots do no see your phone number unless you give it to them. And just as you wouldn't with any other Telegram user, do not give the bots your passwords, Telegram codes, bank account numbers, etc.