Welcome to Airtable.
I found a link for an Overview of Airtable. It starts basic and progresses from there and it does cover Select and Multi-Select fields and other fields, such as Single Line and Multi-line text fields and attachments (images) field, there might be other options for including images and instructions, just to let you know. Keep in mind the overview is just an overview , but it does cover everything and it’s a good primer.
Here is the link for the basic overview:
I also found a guide to all the field types:
I am guessing that you are aware of the different base options and pricing. Here is a link for just that. Keep in mind that the pricing is in USD and there is a slider at the top of the page, if you want to know what the yearly prices are and the monthly prices (a little bit more per month):
The first link was provided for by an Airtable member and I bookmarked for whenever there is a post similar to yours, so it has come in handy.
The other advice I gleaned from the Airtable community is before you begin, read the information (links above) to start with and then decide what it is you want the database to do, in your situation, and then go from there.
I hope that this bit of information will get you going, sorry I was unable to help with your other questions. I am sure there are others with the expertise to help you further.
Hope this helps and that I am not too far off the mark pertaining to your post.