Be very careful to archive the exact version of the article that your journal permits. If it allows a preprint and you archive the publisher's version, you are in violation of copyright and the consequences can be expensive and disruptive. You can look up the exact terms for depositing/archiving at SHERPA/RoMEO.
At present, Empire State University does not have an institutional repository. Complying with a SUNY mandate we are in the process of developing Open Access policies, processes, and an institutional repository for Spring 2020.
Despite the .edu domain name, Academia.edu is, like ResearchGate and Mendeley, a business. These sites are a combination of content aggregator and social networking site for academic researchers. Google Scholar indexes them, and they have alerts which can be helpful for getting your article read by more scholars. However:
They're popular, and if you do have the right to put your article up there, you may decide that the additional exposure and opportunities for social networking with peers in your field make it worthwhile. But you should also deposit your article in an appropriate disciplinary or institutional repository.
If your publication contract permits self-archiving, then you may certainly put your article (or at least preprint) up on your personal website. This may be a simple and straightforward solution, however, it has major downsides.
So while it's fine to put your article on your website, you should also archive it in an appropriate disciplinary or institutional repository.