I went to school at RIT in New York and have dated someone deaf (cochlear implant though so idk if you consider her "deaf" or not)
I consider my self conversational in sign, im not the best with it though. It took me about 5-6 months of somewhat regular interaction to get there. My biggest hardship (still) with ASL are signs that are very close to each other --- examples (orange, old and ice cream) all have very similar movements right around the mouth area.
Also, as you might though theres ASL (real sign) and ESL (english sign). Most hearing signers learn ESL -- so for example youd sign (do you want to go to the beach now), well in ASL youd sign (beach you want to go *point at arm for time* now)
Best of luck with ASL!