Step 1 - actually learn the common baroque ornaments - as ornaments, not as part of pieces - so you can do them with a range of fingers. Ornaments used actually varied quite a bit over time, over distance (eg, French ornaments are a bit different from German ones), and from composer top composer. The Bach ones are the most common, and I think they'
re mostly set out on the Wikipedia page for ornaments, or in the preface to many Bach editions, or you can just google them.
Step 2 - have a look at where they are used in scores where they are extensively included to get the hang of where they might usefully go.
Step 2a - It may be useful to read Fux's book on counterpoint, or at least skim through it. Not essential, but useful as an adjunct to 2.
Step 3 - Sit down at the piano and play around. It will probably start off feeling very awkward and the result will probably be terrible. That's fine. Just keep at it, noticing what works and what doesn't. It's this practice that will get you comfortable with them. There's no one absolutely correct way to do them, just ones that sound good and ones that don't, so use your ears.