Hello everyone :) Can anyone give me any insight on how to sell stocks? Am I suppose to type something in the upper/lower threshold box or can I just leave it blank and click sell?

Basically I'm wanting to sell some of my stocks and I already went on with the transaction.. but the status is still 'waiting' and it's been about 30minutes now. Do stocks only sell at the end of the day or something?

Thanks in advance to those that reply :)