BtM is quite a bit faster than its Florida cousins. It's a thrilling ride but not scary imo. There are no inversions obviously for a start.
If you weren't bothered by coasters before then I'm sure you'll be fine with BtM.
Then there's Crush which depends upon your tolerance of spinning - some people hate those kinds of coasters more than anything!
Indiana Jones is the next stage up. Because it's relatively small it's one inversion (a loop) can feel less tame than it looks but that is really its only big moment.
Lastly, Space Mountain and Rock N Roller are extremely similar. They're both launch coasters, both in the dark, both with multiple inversions - loops and corkscrews. SM's refurb has made it smoother but RnR still gives the better ride experience imo. SM gives you a bit of a beating and I think it's the coaster I've been on that requires YOU to have the most core strength to make it more comfortable