Honestly you shall try all of disciplines and look what works better for you on a distance. Tournaments and ring games have both their pros and contras. I would go through some main points to examine those differences of both.
TIME: Cash is very adjustable to your free time. No matter if you have just 10 minutes or 3 hours, you can play that much
hands accordingly to free time you have. However it's smarter to wait until big blind before you come in and going hand before you will be at the big blind again. With tournaments you have to invest much more time with SNGs (depends on structure) 30 minutes till 1,5 hour per game and with MTTs i would say 2-3 hours as minimum to reach final table, at some big MTTs, like on
pokerstars running it could take way much longer, some games need even like 7-9 hours to get to the final table.
MATH: Mathematics at both is different too. If at cash every 1 of your chips is equal 1cent (or dollar/euro whatever currency you play), at tournament there is only buy-in and the chips are only a part of all chips count, which you need to collect to be the winner. And in fact there work different rules: more chips you have less they worth. Also need to thinking about Harrington's M numbers and play accordingly. Honestly at cash poker math is more clear, than at tournaments.
RISKS: Cash is more risky indeed, because of it's nature. You can loose all the money on table just after one sick cooler. At the tournament you can't loose more than buy-in you made. And most time stacks are so different at tournament, that if you probably still have chips to play even after got beat. Well of course you could use your money more conservative and play lower cash limits to decrease your loses in case you have an unlucky day. But you shall be prepared, in cash if you are unlucky, you are loosing way much faster.
NOTES & PLAYERS: At tournaments (especially MTT) you will face pretty random players and be likely thrown from table to table after some amount of hands. At cash you could play with the same people for hours and find them easier at next days, just going through cash tables and look where your favorite fish is.
WINNINGS: Cash is more like earning money, rather than winning. You are rarely win there big and when it happens its rarely x3 of your stack. At MTT you will have different feeling of something big happens, when you reach final table and prizes jump up with every next place like crazy and you able to win like x100 or even more of your buy-in money. It happen not very often have to admit, but when it happens, you'll get your feel-good-chemicals-kick, i promise.
So it depends on you. What works better for you, which kind of poker do you like. I have chosed SNGs, because its more like golden middle about time investion, but playing also MTTs when i have time for. I used to try cash games many times, but most times it was a bad idea. Therefore here is a tip from me: do not play both! Try them all out and choose at which you will be specializing, do not spread yourself. Better being good at one, than bad at everything.
Good luck at the tables!