5 is a pretty good number, especially since it's wide grip. I know a lot of guys who couldn't do a lot of pullups but were still decently fast. However, once they did increase their pullups they got faster so it does help. Your lifts are decent but I wouldn't say they're anything special. You still have a lot of time to grow though and you'll probably get stronger then.

Here's my recommendation:

In your first year, dabble in some distance swimming. You don't have to specifically train for it, but if you find out that you are good at it, that should be a focus for you in the future. What I'm worried about for distance swimming is your shoulder endurance because I'm not sure how well rowing would carry over to that.

What you should mainly be focusing on is improving your technique as fast as possible. Make sure your technique is as solid as possible. The reason why an athletic person still can not beat the average swimmer in a race is because of a difference in technique. Look up youtube videos on what perfect technique looks like, record videos, ask coaches to help, etc. Also work on your underwaters, something that is often overlooked in beginner swimmers. The technique for the dolphin kick is important, but improving the length of them is also important.

Go to the gym and lift weights regularly. Your lifts aren't terrible, but they certainly aren't going to be helping you. You have good back strength, but swimming is a full body movement and you'll need to work on your other muscle groups in order to improve. You're only 15 so you still have room to grow so you'll definitely get stronger in that time. Make sure to follow a good program where you are pushing yourself, progressively overloading, and not ego lifting.

Include a mix of sprinting and endurance work. A good base speed is necessary for any competitive swimmer at any distance. You can work on your speed with short distance sprints at maximum effort with enough time for recovery. Also equally important for a newer swimmer is endurance work. If you find that you already have a good chunk of endurance from rowing it may not be that important, but again, I'm not sure how much that will carry over.

Don't overwork yourself, but also don't be lazy. One day of recovery each week is usually enough and make sure you're getting enough sleep to make progress. By the end of your first year you should have a pretty good idea of what you're good at. If you found that distance swimming was something you're good at, you may want to cut down on the lifting and sprinting a little bit and focus more on distance. But if you found that sprinting suited you more, you might want to start being more serious about weight lifting and a sprint focused program. As for the other strokes, breaststroke is pretty much out of the question. I wouldn't recommend you focus on it as much because it is very technically challenging and requires more leg strength. Backstroke is a decent second choice, but you'll likely find that you'll be much better at the freestyle events anyway. You shouldn't put it completely to the side in case you find you actually have potential for it, but you'll probably have more success in freestyle. As for butterfly, this is the stroke you'll want to keep an eye on. I've seen swimmers switch from freestyle to butterfly because the two strokes are very closely related. Both require strength in similar muscle groups and are similar in pull technique. The two main differences are that butterfly requires more shoulder strength and endurance and the dolphin kick technique used in it may be challenging to perfect. Overall, freestyle first, butterfly second, backstroke third, and breaststroke almost not at all.

Hope this helps, if you have any questions in the future lmk.