Those are called "key signatures," basics that you'll have to learn. You can't be said to be "ok at reading music" if you can't play in the basic keys that have a few sharps and flats in the key signature.

Regards,

Wow, focused effort on sight reading? I gave up on ever being good at sight reading. I just read music for fun, if I need to take a hand off because the piece I'm reading is hard so be it. Not going to bother looking through stuff I don't really like.

How is that going to help? I have no problems with scale

Let's just put it this way, if you don't feel as comfortable in B major as in C major, you're definitely not anywhere close to being okay at reading sheet music :P

If you're playing in Ab and aren't sure if the D is flat or not in the key signature, then you need to play your scales more. It needs to be second nature

Chord progessions help a lot, too!