Press Track (T!, T2, T3 etc) + Play to start and Track + Stop to well…stop.
If you’re beat matching the playing track and can trigger right on the beat fine, otherwise set your launch quantize to say 1 bar (16/16)
Track (T1 etc) + Bank/Edit to open the sample edit menu
Then Press Effect 1 and scroll down till you see Quantized Trig. Adjust to taste.