re sleeping pads, if you are fine sleeping on the ground without one (cold notwithstanding) then thats up to you. If you haven't camped much though, there are a whole ton of good pads out there, in all kinds of price ranges. The inflatable ones make a real diff in sleeping comfort, and if you want super simple, and for little cost, folding or rolled up foam type ones (even Thermarest makes these) may be fine for you.
I'd suggest going to an outdoor store like REI on a slow morning, and laying down on all kinds of mats on the store floor, thats how I made a decision getting a new mat after ages of using the same types in our family.
There are all kinds of thicknesses also, but like with everything, it comes down to balancing cost/size/weight/comfort, and what works for you.