The short answer is: Maybe.
You're new to the game, so chances are that you aren't that good (no offense). LoL is a deceptively simple game on the surface, but the strategy is deep and complex. I know because I didn't get that for almost 2 years and just whined and moaned about not being able to beat certain champions.
Katarina is a great example, because she can absolutely destroy an entire team in the right conditions, but she's completely useless against some teams. It's more about who you're playing against rather than which lane you're in.
I try very hard to communicate in the lobby with my team. I'm certain that this one change I made has led to my recent performance improvement. The key thing I'm concerned with is the composition of our team. Very often someone will say, "Counters don't matter for X reason." This is statistically ridiculous, and I've lost count of how many times those people get their faces smashed in by the counters that "didn't matter".
So, instead of worrying about where you're playing Katarina, you need to worry about whether or not she's right for the team. If you played in bottom lane, chances are you took the spot from a Support champion. Katarina's abilities are not at all designed to be a support. She generally gets a lot of kills, but would starve the ADC in doing so (I've actually had a Katarina support and she took all the kills).
So, in the end, you may have been fine if you had played mid, and led your team to victory. Or you might have been countered and destroyed, hopelessly feeding the enemy team and getting behind.
TLDR: Learn when to play champions, not where to play them.