You’ll need a domain name to start. If you plan on hosting any communities, you’ll want to secure it as well, I’d recommend a cloudflare account, use their DNS proxy and then only allow traffic from cloudflare cdns so as not to expose your server directly. You’ll also want to configure the Web application firewall to block bots, known malicious IPs, that kind of stuff. To manage this, you’ll have to host your DNS in cloudflare and create and install an origin certificate on your host server.
If you are comfortable with Linux and command line (you’ll want to know at least the basics to get you by), then you can deploy via ansible. Lemmy has a nice little doc that mostly covers everything.
Feel free to ping me if you have some questions.
Oh and if you are having your instance send mail, you can use the service built in, but it’ll get flagged as spam. You’ll need either a SMTP relay service like sendgrid or SPF records so that receiving email servers can verify its coming from your domain.