Welcome to the club and forum, Kristyna!
I was on the freshwater side of the aquarium hobby most of my life, and then started saltwater in the past two years. As you said, saltwater aquariums can get expensive quick and are more difficult than freshwater aquariums, but I've found them to be worth it. You can keep going saltwater cheaper and easier depending on the fish, corals, etc. that you choose. Basically, the hobby is as expensive as you make it.
Anyway, post any questions that you have on the forum, and we'll try our best to help out. Hopefully, we'll have even more members in the near future that can share some advice and knowledge as well.
Also, you should post pics of your 10 gallon in the "Tank Showcase" forum, so we can meet your fish!