Yes, both are stressed on the first syllable so it's actually FI-ka and FICK-a. In fika, the i is long and the k short; in ficka, the i is short and the k sound long. For people who only speak Russian, the big problem of course is the difference between long and short syllables, but since you're also a native speaker of German, that's not a problem for you.
All two syllable words in Swedish have either akut accent (= accent I) or grav accent (aka accent II), but the difference is rarely distinctive. In some dialects, they are never distinctive. In some cases, which accent a word has also varies between different dialects.
fika is accent 1 and ficka is accent 2, but in reality you can ignore that – the most important difference between fika and ficka is the respective length of the vowel and consonant.
I'd also like to recommend the great videos by blehg, there's a list here where you can find a link to a great one about pitch accent: https://www.duolingo.com/comment/6502614
To me as a native Russian and German speaker they sound identically stressed, since "our" (both Russian and German) stress depends on "accoustic intensity" - ie loudness and distinctive pronounciation, rather than tonal features, that Swedish seems to be using in some cases. That's where my question comes from.
Tack så mycket för hjälpen!
I think this is crucial knowledge for beginning learners of Swedish. Had I known this in the beginning, I would have memorized the accent with the word from start... (Though I think I can remember most of the pitch 2 words my friend uses frequently, since they have a very distinct sound)