Create API’s for custom-post types & custom queries using REST or Graphql

I want to create a cross-platform app using rest APIs for the website (zoetalentsolutions.com). The website is in WordPress and has custom post-types, fields & custom queries.

This app will not have any user auth.

What I want is to get custom post-type (in my case: courses) in REST & need to run a custom query (custom meta-query).

So I need a little guidance:

1. How to create REST API for the custom post type
2. How to create end-point for a custom query.

Any help would be appreciated around this.
I’m not expecting a thorough and but a details steps with brief would be helpful.
I believe the second question needs to be asked as a separate but I only need a brief idea of it.

Thank you.