Mrna: gcuaauguc what amino acids does the mrna above code for? what type of amino acids or function are uag, uga, and uaa coding for? which codon (3 letters) signals translation to start and also codes for the amino acid methionine (met)?

So, everything you ask is wrong. Firstly, the mRNA above doesn't code anything, it's false because in order to code something you need a start, the code AUG, which is met.
The amino acids you are asking for are nonexistent. This 3 triplets are excited, because when our ribosome sees one of this it stops. No more tRNA and no proteins for these three. It's like a train, that when meets one of these three stops to make proteins.