My answer as to what I would do if I were dropped off in 1985 with no way back is essentially a combination of other people's previous answers.
First and foremost, I would somehow have to establish and assume a false identity for myself complete with a valid social insurance number etc. Unfortunately, I honestly have no idea how I would go about doing so. Presumably an unscrupulous individual who specializes in forging identities would be required, but again I have no idea how I would find and contact such a person, or pay him or her for his or her services. (And I certainly wouldn't tell that person, or anyone else, that I'm from their future!)
However, if I were able to manage that first, difficult step: I would next save up sufficient capital through low-key jobs that I would then invest in companies like Microsoft and Apple that I know would yield a very high return on my investment, to the point that I could simply live off of those returns.
With my monetary needs taken care off, I would then live a very quiet, comfortable, secluded life in which I try to avoid further interfering with the next thirty years of history as much as possible to ensure that I don't create a paradox. I certainly wouldn't try to advance technology faster than its historical pace, or try to interfere with historical events, or give any hints about the future or indications that I am not of the then current era. Moreover, I certainly wouldn't live anywhere near my younger self or any of my friends' and relatives' younger selves.
I suppose that I would somehow try to find and contact any other stranded time travelers with whom I could more safely socialize with (extremely carefully and with great caution), but in general I would be extremely worried about altering history--to the point that I would sterilize myself and by-and-large avoid relationships. That may be a rather lonely life, but the risks of altering history are too great and I can at least comfort myself with my wealth and by enjoying my favourite era of pop culture as it is happening.
Once 2015 comes around, I would very carefully consider whether or not to make my true identity and nature public--but I would definitely not do so prior to the moment that I was originally sent back in time.