My dd is also 2.5 yrs old and has the same story as yours, leading up to pottying.
We never really did any potty training, but she had the tools, knew how to use the potty, knew when she had to go, but wasn't interested in any of it until recently. Then about a week ago she decided to use the potty, and won't have anything to do with diapers anymore. I stuck close to home that first day, and then went numb with boredom and from focusing way too much on her bodily functions. So as of day two of no diaper, we've been out of the house all morning, home for nap, and then out again when she wakes up.
No accidents so far! So we're still new at this, but I'll offer what's been working for us.
She goes potty before we go. When we get to the park, library, playground, Science World, pool, community centre, spray park, etc I show her the nearest potty and suggest she uses it.
I make note of loos along the way, and have no compunction about begging that my toddler be allowed to use an otherwise not public toilet. If she says she doesn't have to go, I leave it at that, with a reminder that she tell me when she does have to go. I check in with her about every ten minutes, which is probably too much, but I am still nervous about being away from home. We don't bring a potty with us, because I want her to use whatever loo is available and we don't use a stroller so no way to really carry one. If it's a big toilet and she's a bit nervous of it, I hold her steady on it and tell her a story so she can relax enough to go.
I think it's okay for us mamas to feel the fear and go for it anyway, if we think our kids are ready.
I bring a spare pair of underwear and spare pants. For the first couple of days, I also brought one of her cloth diapers, in case we went through the other stuff, but I've left it at home for the last few days.
I also bring an old cotton prefold just in case she has an accident inside somewhere (store, library,etc) so I can wipe it all up right away without having to as for paper towel. Haven't had to use it so far.
And I bring a wetbag too.
Our most daring adventure was a loooong tricycle ride to the doctors yesterday. It was ten city blocks there and ten city blocks home. I kept asking if she had to go, and finally she stopped her trike and looked at me and said, "I'll say I have to go potty when my body says I have to go potty!" We made it home dry, with just one potty stop along the way.
She had to go in between loos the other day, and so she went on the grass. I'm with lifeguard (Hi lifeguard!) ... if dogs can pee on the grass, then why not a potty-learning toddler?
I, for one, would rather have five accidents a day than stay home! Go for it, mama! One or two accidents might be all it takes. Or he might surprise you and have none! Good luck!
ETA: I've added a bit of ground flax seed to her yogurt in the morning, just to make sure she doesn't get constipated. And I make sure to offer her lots of water, because I'd rather she have a few accidents than get a bladder infection from holding it in.