How to create editable sections in wordpress?

Here is what I would recommend.

Use a plugin called Advanced Custom Fields.

This will allow you to build out the admin and have different fields for each section. You could have an editable area with a editor for the about us section. You could use a Repeater Field for the gallery, and much more.

Once you have all the fields in the admin, you just need to pull all the data into your homepage template. This is pretty straight forward and there is good documentation with examples.

This is one of the few plugins I recommend, but when it comes adding custom fields it doesn’t make sense to not use it.