Given hacks like lifetaker, it isn't too hard to get a decent rank and gp perms of weapons in CA now. =/
LoL on the other hand takes ages to unlock champions and such. If you want to try out champions, then look up the PBE Server. (Public Beta Environment). It's for testing bugs etc, and Riot gives you Riot Points and IP to buy things for the tests. It's separate from the main LoL server, but at least you could try some of the champions that you are interested in.
You can also do cases daily in the tribunal. You get a small amount of IP as a reward for each case if you guess the right punishment. If you plan on spending real money on the game, buy a champion pack... and only buy champions for RP when they are on sale. Sometimes they are as cheap as 75% off. Also remember that you can eventually try all champions because Riot has their free champion week cycles.
I would be willing to be your friend on there, if you want. Same name on there as on here.