Question for the more veteran runners out there. How long did it take you to figure out your optimal distance for competitive (even if your times aren't close to elite) running? I'm mostly happy that I can run 30 minutes without stopping on a good day (maybe 20 on a bad day) at this point, but maybe too much time working with spreadsheets is making me curious about this. I'd guess 2 months is not nearly enough time and that I need a good bit more training to really figure out what distance I'm most competitive (or least uncompetitive, let's be honest here) at might be. I'm enjoying the process of getting in shape, but I do enjoy keeping track of this stuff.
My 400m sprint time suggests I should be running a sub-25 5k instead of the sub-30 I'm at now. I'd assume as I build endurance, my times over longer distances will improve relative to raw speed in sprints.
^ ...so my curiosity is more finding the distance that I'm best at, relatively speaking. I figure there are plenty of 5Ks, 10Ks, and (maybe someday) half marathons around to have fun with. I probably wouldn't attempt a marathon unless I got significantly faster at running, but get why other people enter them; I'm starting to enjoy running but just can't imagine doing it for the 4+ hours (at today's speed, probably 5+) it would take me to complete that distance.
2 months isn't very long to determine what your preferred distance is as you may not even know your capability yet. I'm not sure I'd call myself a veteran runner, but I've ran quite a few miles during the years and can say I've hit several distance races so I'll toss my 2 cents in.
I believe that the first year of running is the most difficult and most needed because it is more about getting in shape and getting your cardio and physical performance ready to go farther and/or faster. A lot of people want the results very quickly to be a 5k, marathon, or trail runner, but it isn't that easy. You have to train and ease into shape without getting hurt. It isn't fun...yet. It becomes fun when you can do what you want and see results. Once you are at the point where you can run short distances fast (5K-Half) or longer distances fast or slow (marathon or more), you can determine what you enjoy and what you are good at. I started running and took me 3 months to be able to job 2 miles. Then added more distance, trail running, speed, etc. I am not fast at short distances but found out that I can go quite a long ways at reasonable speed and really enjoy that. Running trails for hours is one of my favorite things to do. My bro-in-law can do both but hates long races and is really fast at shorter races so he sticks to those.
Make sure you are training a variety of different drills during the week / month. Hills, speed work, slow long runs, tempo, etc. to help build endurance and strength. Lots of books and articles out there on them. Pick a local or destination race to help with the training excitement. You can always move up or down the race distance. Either way, you get in shape, feel better, and are able to determine what you enjoy the most. The key is what you enjoy and what you will stick with. If you don't enjoy it you won't stick with it.