I personally suck at pawn, so the only I can help is just giving advices. I add here some infos how to do the pizza missions.
1. You go to Well Stacked Pizza, type some command. -> typing command !pizza, check if you are in the specified location, you can use GetPlayerPos and a XYZ point to calculate the distance between the player and the point, check if the distance is short, then start mission.
2. It teleports you to a place, where the pizza should be delivered. -> easy, a message "ok now you need to get here" and chooses one of e.g. 10 places. Use timer to take player back to the Well Stacked Pizza.
3. Now you have to go to the place and type !deliver. -> start a 1 minute timer that saves some information.
4. If you are fast, you will earn a tip. However you earn money. -> type !deliver, check location. If no data was saved with the 1 minute timer, give player 100 dollars. If there were something, that it tooks too long, then only 50.
Hope that maybe that helps more.