I think if he has watched you on the toilet and wanting and then saying that then it maybe best to use the toilet instead of potty my son used the toilet and didn't like the potty he was the same as your lo. He has now been out of nappys for 4 months now and no accidents
My dd1 was around that age when she started showing an interest in being potty trained. My dd2 is doing it now, and he's 2 next week We sat ours on the potty in the morning first thing, and before bath time. Dd2 has the occasion accident, but doing surprisingly well. Just makes it difficult as I currently have a broken leg. Dd2 asks to go to the potty too, and holds herself. We give a Smarty after each successful wee/poo.
How old is he? He is showing good signs so you could give it a go. I would use whatever he is comfortable with to start with, he will graduate to the toilet in time. We went cold turkey and it worked for us. Be prepared for accidents!
I took my hv advice and bought a potty to have in the house so ds would get used to it. the past few days he's been trying to watch me wee. This morning he said 'I need a wee' sat on the potty (nothing happened), then asked for tissue and wiped himself. I know he is just copying me but does this mean he's ready? eek! how do I do this?? also, the nursery use teeny tiny toilets not potties, we have a toilet seat for him are we better just dgoing straight to that?