A lot depends on exactly what you want to do with it. Some applications, like blueprinting houses, have specialized programs for such things.

I use an old version of AutoCAD. Actually, Release 13 if you can believe it. Like a lot of people, I don't really need all the bells and whistles, and the newer ones are expensive. Even AutoCad LT is something like $900 now, and regular AutoCAD is around $4000. This is twice what it used to be.

I suspect there are free, or nearly so, solutions that will work for you. If you look under "free cad software" or something like that, a lot of things come up you could try.

A sample page here.