When we first started we would just put DD on her toilet after she woke up from her sleeps, mostly she would wee at that time. From there it just kind of progressed to 'lets go do a wee' and if she was happy to we would pop her on the toilet, sometimes we would get a wee others we wouldnt. If she really didnt want to sit there then we didnt push the situation.
We found it easier without any pants but then came the problem of getting her to understand knickers arent for weeing but Im pleased to say she finally got it
If you are relaxed and full of encouragement and praise, she will get it much quicker. Try not to get frustrated and it will make it easier on you!