Creating A Website

This is a very broad question, and you've provided no facts about what kind of website you want to create, so here are some general concepts:

You need to form a limited liability entity like an LLC or corporation and do business under that entity.

You need to clear your domain name and your trademark for availability and viability.

You can copyright the online content. Please see the link below.

You need liability and advertising injury insurance.

You have to adhere to the "safe harbor" rules to avoid copyright infringement claims if your site hosts content generated by others.

You need a privacy policy, disclosures, terms of use tailored to the type of site, and disclaimers, as appropriate.

Obviously you should see an IP/business lawyer to guide you through all this.

Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.

While your question is extremely broad, given the nature of the sites you are looking to emulate are primarily social networking oriented you should study the two following laws closely. These are the Digital Millennium Copyright Act and Section 230 of the Communications Decency Act, which deal with User Generated Content/Copyright and Defamation/Other items respectively.

I hope this helps.

Disclaimer: This answer is for informational purposes only and does not constitute general or specific legal advice, nor create an attorney client relationship.