So I plan on starting with stop motion.

As an aspiring filmmaker with social anxiety, I plan on starting out doing stop motion movies by myself with action figures/dolls and other toys. I do Sci-Fi.

Of course, I have a question that I don't know if anyone can answer.

For Space scenes, since I will be doing it in my room/basement, how do I make the background more spacey and less roomy? Is there some program out there?
black cardboard with pinholes and light behind it. :P

I did that in 2000:

You don't have to be afraid of people: most don't bite...
Here's what I did for one of my films:

Make the background black, either with cardboard or cloth. I actually did my shots outside at night with dark trees far in the background. In post, pull the background down even farther until it is 100% black. Take some photos of the night sky or find free Nasa pictures, and composite your shots on top of them. I did my compositing it Blender, it's free and open source and there are tons of tutorials around for it.
I started out doing stop motion about eight years ago and I would make my own Doctor Who episodes using Lego characters, Lego TARDIS, sets, etc.
For the space scenes I originally used rear projection: suspending my models in front of a space picture. Eventually I used black card with backlit pinholes to look like stars.
A few years later I stumbled across a great website that had free plugins for (the original) Windows Movie Maker that let me do really crappy, basic chroma/green screen effects.
Hope all goes well with your project!