Both are good and viable options in today’s poker scene. You can pick either one and be profitable with enough work and commitment.
However, they are two very different formats, with two different sets of skills required to be profitable and mindsets required to stay sane. No one should know your skill set and better than you, so its up to you really.
Here are some pros and cons of each format. Maybe they will help you to make up your mind.
Tournament pros:
1) When you win, you win big
2) The field is softer than in cash games
Tournament cons:
1) Too much variance
2) Time consuming. Once you register in a tournament you are stuck there until you win or bust
3) Tough bankroll requirements. Due to high variance, you need a bigger bankroll to withstand downswings
Pros to cash games:
1) Flexible schedule. Unlike tournaments, in cash games you can play when you want, and how long you want
2) More postflop play. Since there are no blind levels, you can focus on your deep stack post-flop game and exploiting your opponents
3) Less downswings.
Cons to cash games
1) Too many regulars. These days it is hard to crush even at micro stakes. You really need to be a top players to succeed
2) It gets boring with time.
3) You will not have huge paydays even when you run super good.
There you have it. Hope this is helpful, an good luck!