I trained two of my kids at that age. Ignore the people who tell you it's too young. It might be, it might not - you'll soon know!
The way we did it:
Week before, went to shops to choose big girl / boy pants (buy lots!). Got a potty book (for the kids) out of the library. Bought some stickers and chocolate buttons. Clear diary to be at home for the week without interruptions.
We didn't have a downstairs loo so kept one potty in upstairs bathroom and one close to hand downstairs in the kitchen-diner (lino flooring so easy to mop up accidents). Offer regular drinks to ensure lots of wees.
Sit on potty every 20-30 mins for a couple of minutes max. Stickers as a reward for sitting. It's highly likely that the first few wees will catch them unaware when they're playing / walking around as they don't recognise the signal. When that happens, whisk them to the potty ASAP and if any ends up in the potty, make a big song and dance about being a clever girl and doing a wee in the potty.
By day 2, they were starting to feel and understand the need to go for a wee and would ask for potty (although not necessarily in enough time!).
By day 3, we were down to just one or two accidents.
By day 4 we braved a trip to the park (very close to home!).
Poos were much easier to anticipate as they had a regular time to go so we just got them to sit on the potty after breakfast. Use chocolate buttons as bribery if necessary.
We used pull-ups for car journeys (just in case) for the first few weeks but worn OVER their pants (so they still feel wet) and never told them that they were absorbent like nappies. We called them 'travel pants'.
For naps, I used bed mats / a towel and got them to wee before the nap and as soon as they woke. I don't think that either of them wet during their naps.
At night-time, we continued wearing a nappy but both were spontaneously dry within 2-3 months of being dry in the day.
If no progress by day 2/3, leave it and revisit in a few weeks.