How long does it take for a credit card payment to reflect on your credit report & does the purchas amt matter

im 19 years old and recently got a credit card about a month ago, after getting advice from my cousin to get my cousin to start getting my credit built up he said I need to get 2 and get the seasoned (have them for about a year making all payments on them) i just got my first bank statement in the mail and am about to pay it off, I need to apply for my 2nd card but im waiting for my credit to show from this payment b/c no other companies will approve me with no credit and without having a cosigner, how long does it take to show up on my report? Also do I need to be making big purchases every month for my credit to be better or does it not really matter? and do I need to make a purchase on my card every month to get it seasoned?