The whole category in one page.
BEFORE BUYING ONE
Name the specific thing you cannot do on shared hosting.
If you cannot, you do not need a VPS.
MANAGED OR SELF-MANAGED
If client sites depend on it, managed.
If you are asking whether you can manage it, that is your answer.
THE FIRST HOUR ON A NEW SERVER
Update everything Change default credentials Key-based login, passwords disabled Firewall configured Backups and monitoring
A server exposed before it is secured is attacked within minutes.
THE THINGS THAT CAUSE MOST COMPROMISES
Something out of date Something exposed that should not be
Neither is exotic.
WHAT NEVER TO DO
Set permissions to 777 Expose a database to the internet Run every site as the same user Skip updates
WHAT TO DOCUMENT
Everything, kept off the server.
THE TEST
Could you rebuild this from your documentation and backups?
WHEN TO MOVE BACK
When you are not maintaining it. That is a sensible decision, not a failure.