You cannot change your own site.

This is not a technology problem

A site can be built so the things that change most often take five minutes to change, or so that every typo needs a developer. That choice is made while it is being built, and usually nobody discusses it with the client.

The goal is not that everything should be editable. A sprawling admin panel where you can break the layout is often worse than none. The goal is that the things which actually change can be changed.

What you should be able to change yourself

• Prices, offer and scope of services.
• Contact details, hours and address.
• News, dates and seasonal notices.
• Photos and descriptions of work or products.
• Anything customers ask about most often.

What it really costs

An out-of-date site costs in places nobody counts: in calls correcting the price list, in customers who did not ring because they saw stale information, and in your time spent emailing a supplier about a comma. It rarely shows on an invoice, and it does show in a working week.

Fix or rebuild

Sometimes adding simple editing to the existing site is cheaper than anything else. Sometimes the site is built such that bolting editing on costs more than building it again properly. The answer depends on what it stands on — and an honest supplier will tell you after looking, not in advance.