<p>I've recently bought a 3D printer and waiting for it to be delivered I've given quite a lot of time to looking things up on Thingiverse. I see people create incredible models with gears, screws, lids and a lot of very cool and functional connectors (there are some project for boxes with an iris tipe lid that can be printed already assembled as a single model). I'd like to learn to do some of that as well. At the moment I have some proficiency with Blender where I can navigate the interface and sketch up some simple shaped model without any of the functional parts described above. My question therefore is:</p>
<p>Are there any tutorials that could help me create better models? If I need to I'm ready to learn to use a software other than Blender. I've tried searching for a similar question but found nothing.</p>

The answer to your question is yes, there are tutorials to help you create better models. Unfortunately, the back-story to the answer is beyond the scope of StackExchange.
Don't limit yourself to Blender, especially if you are attempting to create non-organic (engineering-type) models. Blender is great for curves and bulges and bumps (and animation, and so much else) but not so great for parametric modeling. Meshmixer is a useful program, but more organic than engineering.
Consider to search for OpenSCAD, Fusion 360, TinkerCAD, but also use terms such as "parametric 3d modeling software" to find a wider range of solutions to your quest.  The above programs are free, there are too many paid programs to list even a small number.
Oh, yeah, stay away from SketchUp for any 3d print modeling. So many failure modes result from models created with that program.