adihz

Hi All, I'm new to the forum. I just bought my first bike an 88 fz600. I also got my license recently so i think this is a great starter bike. I picked it up for cheap but a few things are not working and i don't have a manual so I would ask you guys to help me out. 1.) i gear up and it works fine but then when i gear into the first and stop the bike always goes into neutral no matter what i do or how many time i push down on it? 2.) All my lights work on the bike except the headlights but sometimes they come on then they die again, what could that be? 3.) I need to tune it up a bit to bring it back to life, what oil should i use? how much oil goes into this bike? What else can i change that will make the engine run smoother and better? Thank you all