So I am planning on my making my first terrarium soon. I had a few questions. First off, I am making it in a mason jar, probably a quart sized jar.

I am planning to get moss from a local woodland or somewhere. I am currently living in Boston, MA (for the next two weeks). I will rinse and quarantine it. That is fine right?

As for pebbles/rocks, where do I get those? Do I have to buy certain ones or can I find them out in nature?

Potting soil: What kind do I get, where, and what are the smallest sizes bags. I only plan to make one terrarium right now. So I don't need a lot, and definitely not some 5 or 10 lbs bag. I'm moving to a college dorm room in two weeks, so I don't need to keep it. If I have to get a large bag I can always give the rest away to someone. I know I need to buy it and cannot just find this component out in nature.

I've heard I don't actually need activated charcoal, so I don't think I'll be buying it as that is more money to spend. Is there any other components I need? And how long do terrariums last?

Thanks.