Reducing dependence on someone else.
WHAT IS WORTH LEARNING
Editing text and images Adding pages Applying updates Taking a backup Checking the site on a phone Recognising when something is wrong
That covers most of what a small business site needs.
WHAT IS NOT WORTH LEARNING
Code, unless you enjoy it Server administration Anything you would do twice a year
HOW TO LEARN
Ask whoever built the site to show you the specific tasks you will do, and record the session.
Practise on a staging copy rather than the live site.
WHAT TO WRITE DOWN
How to log in How to edit a page How to take a backup What not to touch Who to call
Keep it somewhere you will find it in six months.
THE BENEFIT
Small changes made immediately rather than waiting, and a site that stays current rather than going stale between paid visits.
THE LIMIT
Know when to stop and ask. Attempting something structural and half-completing it is worse than not starting.