It shouldn’t be hard to find a pattern for what you want (here’s one: link ), but I wouldn’t wing it unless I were an experienced seamstress. It’s not quite as simple as you might guess. For instance, is the waist buttoned, elasticized, or zipped? Different steps for each and different pattern elements.
A ruffled or layered (tiered) skirt is usually full and requires extra material. It’s going to take some extra steps and a lot of extra hemming. You’ll need a seam allowance and/or hem allowance for every ruffle or tier.
If you try to do this on your own, without a guide to help you with order of assembly and so on, you’d better get plenty of extra material to allow for redo.
If I were you I’d definitely buy a pattern. But second best would be to look for a skirt that fits, whether from your closet or from a used-clothing store, and take it apart: use a seam ripper and open it up everywhere it’s stitched, and construct a pattern from that. You can do it in tissue paper or newspaper. Pay attention to how it comes apart—which seam crosses which other seam—and that will help you with order of assembly.