The first thing you want to do is master the first layer. If you can't master this step you will never have good results from the printer.
Luckily Prusa makes this very easy.
PLA and PETG are both very easy to print filaments.
PLA is great when you are starting out, or want to knock out a quick proof of concept as it can be printed at very high speeds if you are ok with it being a little ugly.
We use a lot of PETG here. With some practice you can get PETG to print just as nice as PLA. The advantages of PETG is it can deal with higher temps much better and in general is a little stronger. Not sure if it deals with UV much better or not.
(I printed a bird feeder in PLA in my early days and it lasted about 9 months outdoors before the UV pretty much killed it.)
I think you both have Prusa printers, if so, you should be able to print some of the TPU filaments. These are fun to play with, it is a rubber material and you can make flexable parts with it. This material comes in a rather of "hardnesses" you will want to start with some of the harder materials as it gets more and more tricky to print with it as you get into the softer materials. Keep in mind your extruder is trying to push this material into the hot end. We have printed super light and flexible tires for Konrad that actually flexed under the little vintage plane he had. That turned out really cool. We use TPU on our Carbon Falcons in key areas.
Anyhow, those are the basic materials I'd suggest for you until you have a need for anything more exotic.
I have been trying to get the RC airplane designers to check out some of the nylon filaments as I think they offer a great mix of extreme strength and flexibility depending on wall thicknesses. But these are not going to be a great choice for a machine that does not have an enclosure, and printing them is a little higher on the difficulty scale. Again this is something we use on key areas of our models with great results.
Like OpenTX, 3D printing can get very confusing if you jump around watching online videos. You will get all sorts of feedback, and much of it may contradict someone elses video. This will keep you up all night and get you little progress. I'd suggest just reading through the materials Prusa supplies
slicer like orca 3d. It is an excellent base of knowledge that you can grow from. Stick with one slicer, and don't worry too much about all of the other stuff out there.
If you start with the Prusa Slicer on your Prusa machine, you are going to have excellent results right away. Just tell it what your machine is, what filament you are using, and calibrate that first level and you should be printer very nice examples with very little effort. They have done an outstanding job. You will appreciate this as soon as you try a different slicer.
Yes, eventually you will want to try some other Slicers, especially if you are printing RC models. Cura is pretty popular for airplanes due to its handling of the thin walls for the wings, etc. Cura is pretty well setup for the Prusa printers, so it is not all that bad.
Hope this helps some.. feel free to ask as you go. I'm not an expert on it, but I watch Rafael and know enough to be dangerous. Rafael makes it all look easy and rarely has a print issue.
