I have no experience with Adderall,but i would advise to start slow with coke.
As its been already said a thousand times in this site,you can always take more but you cant take less.
Id buy a gram of coke for each person and start as small as possible,maybe rub some on my gums first and snort a small 50 mg line for starters.
Its true that quality cocaine is hard to find in most places,but nevertheless start small and gradually redose if needed.
Decent and semi decent cocaine has euphoric,up lifting effects,youll probably feel very confident and energetic,talkative and interested in participating in almost anything.Thats why its best to do this drug while having company(i never enjoyed it alone although alot of ppl dont mind).
Youll most probably be able to function,unless you take too much and start acting paranoid,sweating and being kind of psychotic(although this will most definately be prevented if you smart dosing small).
One last thing,in my experience,cocaine comedowns arent as bad as a lot of ppl claim them to be,and the first times youll use the drug youll barely notice them.Intense comedowns usually come to ppl who are addicted and are used to being high on it alot.If you worry about it,try to have some weed or more preferably a benzo.just in case.
Have a good time and stay safe!!