The verb 'join' without a preposition

Hallo

I thought the the verb 'join' is not accompanied with a preposition. For example – one may say 'Please join us!' (but not 'Please join to us!'). I need to know how to cope with the following situation. Let's imagine that someone has an idea to supplement an existing team with some new members. How would they express a suggestion to do it? Would it be correct to say 'Join them to our team!' or 'Join them our team!'. Perhaps none of my ideas are correct. If so, how to build the sentence in a correct way?