It's not too easy to consider whether a Bach Partita might be appropriate for you, even though you have mentioned the inventions, because you are self-taught. Being self-taught means (without seeing or hearing your playing) that it is rather difficult to work out what level you have reached in your development. There may or may not be a few or possibly many gaps in your piano technique and musical understanding.
I'm assuming that you felt ready to practice Bach inventions yourself so if you have no teacher to tell you whether you should or should not try, and you managed to find enjoyment trying the inventions, why not just do what you did with the Inventions and give the Partita a go? It seems to me you have nothing to lose by doing so but possibly much to gain.
The whole point of learning the piano on your own, if you have no plans for teaching or performing at some point in the future, is to enjoy the hobby and develop as much as we can in order to further that enjoyment. If you like the C minor Partita and fancy giving it a try, go for it! No-one is going to criticize you for giving it a try! If you want to learn it for yourself, then just do it and see where it takes you. You may find it enjoyable or you may find it too difficult and less enjoyable but without trying you will never know. It's a win-win situation anyway because the actual effort of trying it will cause you to improve whether you succeed or not. You may enjoy it, you may not but either way, it will be a valuable lesson for you.
If you wish to take your playing further so that you can teach or perform later on, I really do feel that a teacher would be necessary because there is far more to professional piano playing than some might realise.
If you are learning on your own, the best thing you can do is listen to others playing the piece and watch and listen carefully - to rhythms, expression, speed, etc and also choose a copy which at least has some suggested fingerings for you to try. Fingerings for Bach are fairly complicated and bad or poor fingering can slow down your progress to such a degree that it actually takes away your ability to succeed. When you have done this, try recording yourself and listen with a critical ear. How does it sound? When you are playing only to yourself, it can sometimes be difficult to hear when you haven't leaned on a note quite enough, or your rhythm isn't quite accurate.
I have always found that playing music which personally inspires you can be the very best music to try, even if you can't play it that well. Remember, it's YOUR enjoyment that is the most important when you are playing for yourself. It doesn't matter what others are doing - YOUR enjoyment is paramount.
I wish you the very best of luck and happy playing!