I have made the whole post about the promotion of the cam website and you can read it here: https://mradultaffiliate.com/how-to-promote-adult-webcam-site/
However, your main focus should be on the search engine optimization and this can be done in many different ways, one adding content to your blog, getting some links, these are the two most effective ones but remember that it can be hard to rank for general keywords, it is easier to do this if you have a specific niche.