When should I start potty training?

Potty training advice! I have an 18 month old daughter, who is very interested in the potty and sitting on the potty. We’ve tried putting her in training pants and sitting her on the potty every 20 minutes to see if she will go. She will run up to me in her training pants and say diaper and then when we put it on the potty she won’t do anything and then we put her back in her training pants she pees in them. So I know she knows kind of what is going on, but is it too early? Should we wait a couple more months?