Love the light on that shot! I hope you'll keep going with the hobby!
Here are a few things:
"Kit lens" such as this 18-55 of yours are typically not that great. It really depends what you plan to shoot, but going with a prime lens (50mm f/1.8), if you can afford it, or something vintage (Helios) can be a great experience; also for "forcing" you to shoot manual, as other advised.
Great to see you are on Linux! I have no idea about the webcam stuff. I also didn't had luck trying to use a Sony camera myself, but I'm guessing if the proprietary software doesn't work, the only option is to get a capture card for your PC.
For editing, I strongly recommend Darktable, also as advised before!
Shooting manual is rewarding; shooting "blind" (idk if there is a specific word for that), where you estimate the exposure "by hand" is a lot of fun imo, and very forgivable on digital camera! If you can, give a shot at the "Sunny 16 rule" technique. To me, it makes shooting outside very relaxing since I don't have to care about the camera settings that much once it's figured out.
Have fun, but beware! It's a deep, deep rabbit hole.
I've heard Darktable a lot, and I've actually looked at it before, but it looked intimidating and I did not yet really have any photos I could try to edit, so I continued doing that first.
As for the webcam thing: I have a capture card, and it kinda works, but I'm not too sure on how to get a clean output through the HDMI port.
However, I'll definitely look into those things :D
As for the lens thing: I don't think I'll spend money on new lenses immediately, and if I was, I'd look for cheap used ones. I kinda wanna create art and not necessarily perfection, and also I don't like spending money xd
I think it's about finding character in the gear you have.