Stradivarius

Sorry... I don't understand.

In a lot of Bach's fugues, he uses a rest at the beginning. I've never understood why and how to use these. Hoping someone can explain why and how to write a piece using one in the same way, as demonstrated in this picture:

It's alright, I got them all now: I4/2, Isus4, Vsus4, ii6/5.

Ty.

The 6th is f#minor, not sure about that. I tried that in root and it doesn't work.

Ty. Yeah, I think you're right. One more, if you all could help me.

Can someone tell me what the chords are in these 3 pictures? The piece is in A major. 🙂