First, take a look at the tag in your door. On it you'll find the ratings for your pickup. GVW is how much weight your pickup is rated to haul with no trailer. GCVW is overall weight of pickup and trailer combined that it is rated for. Also should be how much each axle is rated for.
Second, look at your tires and read the sidewall. You'll find your tires weight rating there and what your air pressure should be to achieve that rating. Multiply that figure by 4 to see what your total tire capacity is. If it is less then what your pickup will weigh with trailer attached then you need heavier tires. Run your pickup across a scale to find out how much it weighs normally, that way you'll know how much more weight can be put on it.
Third, find out if you have a transmission cooler (automatic transmission). Without one you can easily fry your transmission while pulling, one can be added if you don't already have it installed. Trust me it will be cheaper than rebuilding your tranny and putting one on at the same time to keep it from happening again. Generallyl they are either in front or behind your pickups radiator, if you know what to look for it will be easy to see if one is there or not.
Did you buy it new? If so and you still have the original paperwork look at what it came equiped with. You are looking for things like transmission cooler, tow package, heavy duty, etc.
You'll want an equalizer hitch (the hitches you see with bars). This will better help distribute your trailers weight on your pickup and make it easier to tow.
Properly equiped you will be able to haul a two horse trailer. If not properly equiped you can end up costing yourself a lot of money on repairs and heart ache.