I have been using Draftsight for a year or so now. It is free from Dassault Industries (the French aircraft maker, they also own Solidworks).
It (Draftsight) is a free download. It is and was intended to be similar to AutoCad but only 2 dimensional. I cut my teeth on Autocad but the price of the upgrades was getting burdensome. Also most of my drafting is 2D. If I need 3D, Sketch-up (also free) has met my needs just fine.
Most of the commands in Draftsight are like those in AutoCad, which is to say the learning curve can be pretty steep if you are starting from scratch. I took a couple of classes on Autocad at our local community college. I was working for a small engineering firm at the time and needed the jumpstart. I am not sure that any cad package free or not is very easy to learn. You just have to pick one and jump in the deep end.
Good luck in your search,
Tim