I have already started on writing part 2 but I haven't even started writing part 1 yet, I know movies do it but is o.k. if you do it in a book also?
As long as everything connects properly, there shouldn't be much a problem. Not to mention, with all the years that literature has been around, I'm sure someone has attempted it at least once.
I think it depends on how closely coupled the two parts are. If the events are mostly independent, if the characters in common between the two parts don't develop much in the first part, you stand a better chance of getting away with it. But if the plot is character driven, and the characters evolve in the firat part from their interaction with the plot, you are more likely to end oup having to force the plot and/or characters in the first part in order to make the transition from part one to part two smooth.
O.k. I wonder how it'll work though because I already know how I want part 1 to be but I started part 2 because I'm kind od stuck on part 1
It's a sensible thing to do. I like to plan my novels and I create scene cards before I start to write. If I'm motivated to write, say, scene 10, I'll do just that, even if I haven't begun to write scene 1. I find this helps me to avoid writer's block. It also helps me to avoid the writing tailing off towards the end of the novel. John