When drumming, if you find yourself off when doing a beat (like: yellow, yellow+red, yellow, yellow+red), it may help to hold your sticks a little looser, if that doesn't work, go to practice and break it down. First the yellows or blues (the faster one) then add red (or the slowest one) then the kick pedal.

On singing, you do not have to say the words, just make sounds that match the pitch. If you know the song, it will be a lot easier so you can know what is next. It is still recommended that you say the words to stay on track though.