Normal discharges and smells

So I have a fear of having a std and I know they only way to find out if you have a std is go to the doctor well I’m setting up an appointment soon for a gyno I was just wondering what is normal discharge and smells of vagina ? Also how would you even know if you have a std I don’t think I have one but I’ve also never had a Pap smear or anything of that sort and I have been sexually active since 14 and I’m 18 now and also when I do get a Pap smear how long do the results come back for you to know if you have anything ?