At the begging part of the game when you can build there at sanctuary. The starting town . How do you get rid of the houses they won't let you scrap , you can only scrap a couple so how do you build a lot of houses/beds ??

Find a house with a roof then scrap the junk inside of it.

Yeah you'll have to build inside the houses you can't break down. I just wish people would stop coming into MY HOUSE. STAY OUT! Also can't for the life of me figure out how to power indoor lights lol