The ONLY AR specific tools I've ever owned are; a DPMS armourers wrench (has 2 typs of barrel wrenchs, stock spanner, flat head screw driver, the wrench for the flash hider, ect, all in one handy tool) approx. $30 and a set of vice blocks for the barrel. Approx $30.
You could use a hammer, tourque wrench, punch set, snap ring pliers. Those tools are what you need for majer jobs like changing barrels and such, you shouldn't worry about all that for just messing around with your first AR.
The only tool you'll need in the field is a pointed bullet, you can use that to adjust the sights, release the trigger guard, dissassemble the bolt/ bolt carrier, that's how the weapon was desighned.
For cleaning, I'd recomend a Bore Snake, some CLP and a tooth brush. Maybe a can of non-clorinated brake cleaner for blasting gunk out of the nooks and crannys.