Redoing basement into bedroom!

My SO and i are FINALLY moving our room to the basement where its bigger. We are living with my mom and the room we are in now is not big enough for the 2 of us and his 3 year old. The only downside we have to completely redo it. Put floors down, paint the walls, clean it really well and the bathroom down there really well (its never been cleaned, or used since we moved in 7 months ago). Only thing is neither of us have any idea how to do any of the remodeling that needs to be done and we can't decide on how to do it. Any tips and advice would be greatly appreciated. Also we can't get a home designer or renovator to help with it.