Some question about first planner

hi everyone, im new and now reseaching about cropter. i have some question.
1: i just only know setting alt in auto mode and in maunal, my cropter speed up too fast :)) my pixhawk was borken cause collision with the ceiling. how can i change the default take off speed and altitude?
2: how can i checking gps signal is already for auto mode or not?
thanks you!!!