Do i have to learn CAD

[DangerousThing]

If You can get an access to Solidworks i would very much recommend it (it's expensive, though). The possibilities are immense and although the learning curve may prove a bit steep for a complete 3D novice, it pays off later on. I don't know what do you plan to do in 3D printing, but in the future Your needs may extend further form laying plastic layers and then You need CAD drawings. That's especially true when you do some models of boats, planes or automobiles.

Both Blender and Modo can do all of that with much less training than Solidworks for a fraction do the cost. That's why I don't list 3dMax or Maya, because they cost much more than the combination of both 3d printers I have on order.

There is also Wings, but I don't know that personally.

There is also FreeCAD, which does some things very well.

I strongly suggest not investing much until you know that you're going to stick with 3d work. Now, if you have access to Solidworks through work or school, you might want to try it out. One thing I've found over the years is that taste in 3d applications is a very personal thing.

[HummaKavula]

I've used FreeCAD. Buggy as hell. There's a reason for software being in 0.13 release. However i'm not some fanatical salesman of Solidworks. I wouldn't use it on my own if I had to buy it for my own money. At least not for 3D printing modeling. And I fully agree with your last suggestion.