the Services Page works like this:
create a new page called for example Services, set Pages Attributes -> Template -> Services.
Now from Customize you can choose whether to enable the various sections within that page (Partners Services Page / Post / Quotation Services Page / Post),
As far as the page ID is concerned, you do not have it in the customize, but you can choose which posts to show in this section on the Homepage.
Create new posts that will be the Services you perform and give them a category (Our services), then from Customize select this category from Settings Services Home Page-> Select Category Post Services.
Now you will have your Services on the Home Page.
To access this page you can for example insert the link in the main menu!
This system is found throughout the Avik theme.
The theme is made in such a way as to always have your content safe, even if later on you decide to change the theme your content will always be there.
I am a WordPress reviewer, and this point is very important for anyone who creates themes!
If you have other doubts I will be happy to help you!