Sketchup feels easier, but unfortunately does not produce good stl’s as it produces a leaky mesh - it works on faces not solids and therefor when you joinr or subtract it makes a bit of a mess.
Use 123D or switch to Fusion 360 as there you are then learning to harness a proper parametric system (And I think it is free to certain groups).
Worth doing now before you get too far into the fun of 3d printing!
