Not much to see, except the busy market. Uribia is just a transit point for 99% of tourists.
Try to find one of the drivers who do tours to Punta Gallinas. They can also take you to Cabo de la Vela, typically they return from Punta Gallinas between 12-2pm to offload their passengers. They may be at the cruce, rather than in town.
Stock up on water and snacks for your trip to Cabo de la Vela and/or Punta Gallinas, basic essentials are a LOT more expensive up north. If going to Punta Gallinas buy some fruit to give the kids at the various roadblocks you will encounter on the way - sweets will rot their teeth!
This is also your last chance to use an ATM if heading north, so bring enough cash to cover your kitesurf lessons, Punta Gallinas tour, etc. if you plan on taking them.
Plenty of places to eat around the market.
Buy at least 5 litres of water if heading north.
Take a 4x4 to Cabo de la Vela. It costs 15,000 COP and takes about 1-1.5 hours. Get out at the cruce/crossroads if you don't want/need anything in the town and don't want to wait - you may be sitting in the back of a truck rather than the front, but you will save a lot of time. Ask around for the drivers who will take you to Punta gallinas. It is better to negotiate directly with them than use middlemen/agents in Cabo or elsewhere. Rainer, Milord and Berni are some of the drivers recommended by hostels in Riohacha.