How do you create a backend?

Question

CMS

For example, I have a PSD site template, I made it up, created a database, and started programming it using PHP. Everything works fine. But here the question arises, how can I transfer such a site to a customer who does not fumble in programming at all? I see two ways out: 1) create your own cms, but it is very long and routine, almost like creating another site. 2) use ready-made cms like Wordpress, but then you need to study its documentation, which is also not encouraging.
The question is, how exactly do you do it, create your own cms, choose from a ready-made one, or is there something else, and which one is better in your opinion from this? How do the professionals do it? I will be glad to any answers on the topic. Sorry if this is too stupid a question.

Answer 1

If the client’s budget allows and there is enough knowledge, we take a framework and make a website with an admin panel.
If the budget or knowledge is not enough, we take and do it on CMS, if you write in php, then it will not be difficult to understand how cms work and understand the documentation.

Answer 2

Learn several CMS, each for your tasks, online stores, blogs, etc.