Is there a kit list in with the instructions? If so then your first task is to identify everything and tick it off on the list. This is the first task for any kit build but in your case you really need to know what is missing before you waste time starting something you can't complete. If you find things missing others on here may be able to point you at sources for replacement.
When you open a post you will have the box you type your comment/update etc in and to the right another box with a + in it . hit the plus and it will take you into your file system. Browse to, and select, the file(s) (can be multiple) then hit open and they will all pop up in the box. Things may be different if you are working from a phone. I can't help you there....too old for that sort of thing.
I have just become the new owner of an AZIZ kit (model slipway). It is unstarted and I am told by it's previous owner, that it may have parts missing, hmmmm. However, I believe I am up to the challenge, so, as soon as we get settled into our new abode and her indoors can't think of anything else that requires my immediate attention I shall make a start.😆 Watch this space!