Another childish image .... that works. Grandma's House is situated within the three black keys. Grandmother (G)"downstairs," the attic (A) "upstairs" ... the front door (F) and the backdoor (B).
Begin by finding all the groups of three black keys and lightly resting your hand on these keys. Next, notice the shape of the G's and A's (like little paddles). Use your 2nd and 3rd fingers to find and play all the pairs of G's and A's. Try to get them to go down together and come up together -- not easy! Next, find all the F's and all the B's, shaped like L's and backwards L's.
When learning your keys, it's important that you NOT rely on counting up through the alphabet (ABCDEFG). How could you possibly read words if you had to consistently go through the alphabet to examine individual letters. That's silly. Same with piano.
Be able to easily find any key on the entire piano keyboard. If you listen closely, you'll notice each key has its own unique qualities. Notice how D rings out, how F can sound a little scratchy, how C can sound a little plain (like vanilla ice cream, without enough sugar).