in this times, thanks to internet its actually not that hard to learn languages
one good way would be like, try to chat with germans daily 10-20min your german will increas rapidly this way in just a few weeks, once u got used to that language try out voicechat (skype, vent, teamspeak) since its completly different to understand a language when u read or hear it

about german its pretty easy language actually (well more difficult then english, but compared to other like russian it is easy)
the pronunciation of german words is always clear (u speak what is wroten) not like in english where u can read "a" as "e" , "a" or "o"

the difficult part is the grammar, the hardest in german grammar is the knowledge of gender of the words, i guess you know what i mean "der die das"


another good way to learn language is beeing an exchange student, a few years back my sister was exchange student with an french school for 3weeks (the whole class did that, pretty common in germany to have such exchange projects once or twice in middle school)
while the class of my sister moved to france, the class from france moved to germany, it was like a replacement for 3weeks, so my sister was replaced by some french girl, who stayed at my house for 3weeks. Well nobody in my family actually spoke any french, so i was the only one who could talk to her, my french increast so much after this 3 weeks, cause after first 2-3days speaking only basics with her (in example parents are asking me to ask her if she is hungry or similar stuff) i got along with her pretty well and we spend some time together
in this school year my french mark went form 4 to 2+ (german middelschool marks are 1 2 3 4 5 6[worst])
that is an example how i learned french, since i was very lazy in school and never study there^^ (though i droped french later in highschool)

coming back to ur original questin, u should study both languages, though you schould first get the basics of one language before you start with another, so you dont mix up stuff