Potty training advice

Rose

Our 2.5 year old is interested in the toilet and when you ask him "do you want to pee pee on the potty?" He gets all excited and runs to the bathroom. He will sit there singing with me for about 10 minutes, but not pee.

I'm glad he's excited about the potty and he seems to understand the concept, but nothing is happening... any moms who have been through this already with advice?