Nutshell:
— Play against strong humans!
Most of the people you play against will probably be your own level, beginners with ae little knowledge as you have. Treat these games as fun competitions and as oportunities to experiment with new ideas and moves. This is where most of the enjoyment of the game will come from. And this is where most of your skills will be tested. So play and have fun. As much as you can, on both counts! :)
Every now and then you will get a chance to play against a strong(er) player, usually with handicaps (explained here), but sometimes without. It might be just a friendly game, or a teaching game when the strong(er) player agrees to give you some comments and pointers after or even during the game. Such games are great oportunities for you to learn and find out if the stuff you already now is good or not so.
And please, treat games against strong(er) players as learning games, regardless of the opponent's perception. Do not get hung-up on the result too much. Do not let your ego grow too large just because you beat this or that player while taking 9 handicap stones! Remember - he or she did not simply found their rank lying on the street - they can trash you at will if they want to! So be respectful, and who knows, you might get another game!
It is true that most computer programs can beat a new player to pulp, even on high handicap. However, unlike their chess counterparts, Go-playing software is actually in its infancy, no matter how much it can crush beginners. The programs play very poor game, and the habits you can pick up by imitating them are almost always bad. It will cost you lot of time and effort to unlearn them. So why even go there?
Best stay away from go-playign software.
However, if you really really want to, below are some links to go-playing programs which you can download and then play against. Just remember what I say - do not rely too much on learning from this software!