Most small-business security advice is written by people who assume you have an IT department. You don't — you're the owner, the ops lead, and the IT department, in whatever order the week demands. This is a list ordered by impact per hour spent, not by what looks impressive in an audit.
Do these first — highest impact, lowest effort
Do these within the first month
Ongoing, not one-time
The takeaway
None of this requires a security budget or a specialist hire. It requires roughly a day of setup time spread across a month, then small recurring check-ins after that. The highest-impact items — two-factor on your critical accounts, individual logins, tested backups — address the failure modes that actually take small businesses down, not the exotic ones that make headlines.