Can i learn more weapons in m effect?

i recently rented m effect and i chose the sentinel cl, since i love magic and stuff like that and i found out that i could only use pistols that didnt me since i saw untrained over the guns and i thought i could learn them in a similar way to world of warcraft where you pay to learn knew weapons not availiable by default for your cl but i just dont know where or how? can someone help me?