Hard to say what your next step should be. A question to ask yourself is if you get into 3d printing what do you plan to use 3d printing for? Prototyping parts? Designing molds for cakes? Toy design?
This would help direct you to a 3d program that would be best suited to your needs if you are looking to design printable models. For example if you plan to use 3d printing to help design parts or molds for parts, Fusion 360 or solidworks may be best. If you are looking to get into toy design almost any 3d program will work. It is also just a matter of preference. I come from a game and software background so I personally like to use 3dsmax and zbrush as the things I create with my printers most of the time are characters, props, and toys. I like 3ds max because I find maxscript (3ds max’s scripting language) a little more robust in automating tasks and building tools to help in my design work. I have experience in Maya and blender but the interfaces and python language bug me. I mostly use Maya for CG work only these days. Blender is a great for a learning tool for 3d in general.
You don’t need to go to school to learn 3d. There are plenty of online tutorials for the majority of 3d software available for free or commercially. Whatever 3d program you do end up going with as a fellow artist I do recommend learning the back end language of the software you choose. Learn the language you can then automate processes in your workflow and save yourself time.