1) I am trying to setup an FTPS server on my EC2 Ubuntu instance. I can only find resources to setup tutorials for an SFTP server. 2)From what I understand, the SSL certificate is only applicable to the server. When a user tries to FTPS to my server, should he/she upload a certificate or public/private key file similar to SFTP? Or only hostname, port, username, password is sufficient?
You might have better luck searching for "ftp over tls" which is another name for ftps. TLS is the successor protocol to SSL, though often still referred to casually as "SSL."
I use proftpd and I mention that primarily because their docs discuss some theory and troubleshooting techniques using openssl s_client -connect which you will find quite handy regardless of which server you deploy.
The SSL cert is only required at the server side, and if you happen to have a web server "wildcard" cert, you may be able to reuse that, and avoid purchasing a new one.
Client certs are optional; username and password will suffice in many applications. Properly configured, authentication will only happen over encrypted connections. (Don't configure the server to also operate in cleartext mode on the standard ftp port; inevitably you'll find a client who thinks they are using TLS when they are not).
If client certs are required, it is because of your policy, rather than technical reasons. You'll find that SSL client certs operate differently than SSH. Typically the client certs are signed you a certificate authority that you create, and then you trust them because they are signed by your certificate authority as opposed to your possession of their public key, as in SSH.