1st time using a stir plate

how long do i leave it on the stir plate? and then how long do i let it set? before i pitch it.

Leave it on the stir plate 24-48 hours ONCE it takes off. Until it takes off, I find I get better results by alternating with the stir plate on for a while, then off for a while.

Once it is done, I generally leave it at room temps for overnight. If it is really done, it will start to clear at the top. Put in fridge for 24-36 hours, decant and pitch.

Not the only way, but the way I do it.

With most yeasts I can fully ferment out a 2L starter in 24hrs on my stir plates. Then I allow to cold crash for 48hrs decant and pitch.

so i would start my yeast 3 days before i boil my wort then pitch. when you say cold crash do you mean to put it the fridge?

Start it 5 days before just to be safe. There is no harm leaving a starter in the fridge for a few extra days.