Roll the windows down. AC is not for the DIYer, honestly. Without a set of manifold gauges and a good knowledge of how the system operates, the DIYer can usually do more harm than good. The newer vehicles are even more sensitive to too high or too low of freon or oil levels. So sensitive that only an ounce or two off, can cause it not to function. Also, many DIYers like to use freon with additives... leak stop, oils, etc. This can also have an adverse effect on the AC system, as some of those additives aren't compatible with what your system calls for. Best to have it checked by a repair shop, IMO.
Best of luck, and sorry to sound so pessimistic but I want to give an honest answer.