I've spent the past 16 years as an IT Manager. Just as general advice...

1) Keep your system up to date and reboot at least a couple of times per week.
2) Don't allow remote connections from anyone you don't personally know.
3) Use a password manager (Bitwarden is free, it is regularly audited by a third party security service, and overall it's excellent), audit your passwords to make sure that they haven't been exposed in data breaches, and do not share your passwords, not even with your mother.
4) Generate unique passwords for everything except for your password manager's master password and the e-mail address that you use for recovery and 2FA. Seriously, you're much safer not knowing what your other passwords are. They'll always be available and you won't have to type them in manually if you have them safely stored.
5) Multi-factor authentication is there to help you. Use it when you have the option.
6) www.haveibeenpwned.com
7) If you're concerned about public visibility of your IP address in multiplayer games, use a VPN service.

Steam titles are generally very safe. There were some exceptions with a few games from China and perhaps Russia that were removed from Steam maybe a year ago.