My first three are potty trained (the 4th is only 13 months), and they have been interested as they near the age of two. But that's usually all it's been - interest. We let them sit on the potty when they want and go potty when they want. We've let them start wearing underwear if they want. But usually their interest starts backing off when they start having accidents in their underwear.
My first I didn't try until she was over three. My second, I decided I wanted to potty train him around age two - around the age he showed interest. And, he potty trained.
BUT...
The level of potty training you get when they are two is not quite the same as when they are older (generally speaking, as I'm sure that there is the rare child this doesn't apply to). When my son trained at age 2, he still couldn't pull his pants up and down. He had to be reminded regularly. If I was busy with the baby, and if I couldn't get to him (which seemed to happen at least once a day!), then he'd have an accident. The amount of effort I was putting into it was silly to me. I had to put so much focus and effort every day to remind him and help him. And, from what I've heard from other parents, it's pretty normal at that age for it to be a lot more work.
For me, it didn't work. I had other kids I had to take care of too (one being a few months old), and so I decided to stop after him being trained for four months.
When he turned three, we started again. All I did was take his diaper off, no underwear - he went bare bummed (best way to train!), and he was trained in a couple days AND he could do it all himself. It was SO MUCH EASIER.
My daughter just turned 3 yrs old a couple weeks ago. We she was around the age of two, she showed interest. She'd even go potty. I put her in underwear, but when she had accidents, she lost interest and wanted her diaper back. So, I never pressured her. I knew from my son that it was easier when they were older (though at age two, she could pull her pants up and down).
Anyway...so a few days before she turned three years old, I told her she was going to get to potty train like her brother and sister. I made it sound SUPER exciting. She was super excited. She had nothing associated negatively with potty training. She did great. She didn't have accidents for the first few days. Then she went poop and pee in her underwear on the 4th day (?). So, I took them off and told her that they aren't for going potty in, so she'd need to go bare bummed for a little bit until she felt like she would be able to only go potty in the toilet (she wasn't in trouble). And, that was it - she was fully potty trained after that. She never had another accident. She figured out how to poop in the toilet after that (that's usually the most confusing for them).
I have totally rambled. Point being - when you train when they are little, you have to be a lot more involved regularly. And they are likely to have more accidents regularly. BUT, if you have no other kids, this could work perfectly for you.
For us, we have learned to wait until age three because of how much less stressful it is for everyone...and how much more advanced their potty training is...plus how fast they learn. But again, if you have no other kids, it might not be an issue for you to start soon.