You know, I've never taught a young young child to potty in the toilet...I have a stepson who entered into my life when he was 11, so I missed the toileting bit with him as a little tike.
HOWEVER...I am a special education teacher, and have toileted MANY MANY older children...some as old as 12 and 13 years old, most having mental disabilities and/or autism.
I have my kiddos on a potty schedule. Each and every hour, at the same time, they get taken to the potty. I create a visual routine with pictures of the steps (pull pants down, sit on toilet, etc.), and have the children sit on the toilet, and I set the timer for about 10-15 minutes. If the child is fidgety or has trouble with their attention span, I've created lap trays out of pop can flats, that have either little fine motor tasks to do, or some toys or manipulatives to fiddle with while they're trying to potty. If it happens in the toilet, I verbally praise to high heaven, and if necessary, I will offer an edible treat, or a preferred activity afterwards. I will most often put the child in regular underwear right away in the morning, but if the kiddo has behavior issues (like wetting their pants to avoid a demand, or to get out of work...yes, some of my kids can pee at will...
), then they wear regular underwear with a pull-up over the top of it. This way, if they wet, they will have to sit in it, and feel uncomfortable, without soiling their pants through. A child must begin to view the feeling of being wet/soiled as aversive, or associate discomfort with it, as this will make going in the toilet more reinforcing...sounds a bit harsh, but that's the way it's been the most effective for my students.
Anyway, good luck! You'll be so happy when this challenge has finally been mastered by your little one!