Hey guys I am planning to make a skyscraper in a city lot that I bought but I really only know how to make the outside frame.The problem is once I make the outside frame how do I start to put in other floors and stairs?

make one block tower

just begin with a good underground were you can start with and build from that further

Just wing it, thats what the greats do (me, reggief)

yea start from a base the slowly build up make it random not just a cube though

EDIT* dont worry about filling in and making floors til youve got the skeleton made