Your runner is beautiful - so lovely that it's hard to believe that it's your first entry into the quilt world!
As for the quilting part, I would look at the software you used for the rose embroidery. I've used that type of outline embroidery for quilting successfully. If there are other roses in that software, you could use them. OR, if your machine has a function that allows you to emlarge a quilting design, you could just enlarge the one you've used. Just figure out a way to lay it or them out on your liner, Then hoop quilt, batting and backing and embroider. You won't need stabilizer.
I put my quilt sandwich together with spray adhesive - Sulky KK2000, because you can use it indoors without worrying about a chemical smell. Cut your backing 2" bigger than your quilt on all sides, tape it down wrong side up tautly but not tightly (on the floor if you don't have a table large enough). You don't want to stretch it. I tape newspaper around the edges to catch any overspray. Cut the batting the same size as the backing (lots of recommendations above - I use Warm and Natural cotton, it doesn't drape as nicely as silk, but it's also not as expensive!). Spray the KK200 on the backing, following the can's directions. I start at the 'top' and work my way to the 'bottom', doing about a foot at a time. If you get putckers or folds, simply lift the batting up and redo it. Pat it firmly down on the backing. Finally, spray the batting and put the runner on the same way, patting firmly, redoing as necessary. I usually fold the edges up on the sides and pin to hold everything together - the edges get a lot of action during the quilting process.
Finally, the binding. You'll get a lot of opinions about that, too. Just ask us!
Good luck! Please show us the finished runner.