Odds of Getting In
We won't lie to you–odds aren't great.
For one thing, newspapers as a printed medium are dying. If you follow the news at all, that shouldn't be a surprise to you, because you've probably never read news from an actual newspaper. You read online news sites or watch TV news networks or just take in whatever stories your friends recommend on Facebook or Twitter.
The point is, newspapers only print what they think will make them money and as an industry, newspapers are losing that green stuff rapidly. They aren't exactly giving away print space. And most cartoonists get rejected several times before an editor likes their stuff enough to buy it.
Larson got rejected more than a couple of times because few editors were ready for his brand of humor. Watterson's first strip idea was a brash, loudmouth space explorer. Nobody liked it, but a few years later that character became one of Calvin's alter egos, Spaceman Spiff.
Point is, it's a tough business to get into.