Ann. Sometimes it's wonderfully useful to have no 'learning curve' (aka--How does this work). Most (not all) of my crafting started with little or nothing to access for lots of info--even supplies in some cases. So you're in good shape--if you can relax & not worry too much about how you 'should' do what you want to do.
First off, I agree with Heidi about getting some watercolor paper. I wouldn't overthink what kind. Long as it has some weight & isn't overly textured, you'll be fine. Trust me, pal!
Next. Make sure you have some ink that is 'waterproof' if you want to use watercolor to color stamped images. StazOn would be my recommendation. And with the 'midis', you don't need to purchase large pads.
Now comes the watercolors... ITA with Heidi that lots of waterbased inks--markers & pads--will work. A good pack of markers (Crayola) may be the way to start. They'll allow you a bit of 'control' so you won't be as concerned about that. You can always get more stuff later, but start simple.
You might want a good brush or two. I'd get a flat & a round. You'll be able to use them to wet your surface; apply, move & blend the watercolor.
If you have access to a Public Library, I strongly recommend visiting it & seeing if they have any books on Watercolor Basics--washes, dry-brush, etc. Unlike the interenet, you can keep the book handy while you're developing your ability--aka 'learning curve'. And... You might pick up an inexpensive set of cake watercolors--those little round cakes of paint that many of us used as kids. Check the kids' aisle where crayons & such are sold.
Hope that helps, Ann. Go forth & have fun!