Dry land exercises for masters swimmer

Hi, I'm a 41 year old masters swimmer. I have no past experience in swimming. Started swimming 2 year ago, took a few private lessons to learn free style. Today I swim about 3 times a week with a masters group, 2-3 Km each time. I'm not competing, but I do want to challenge myself and improve my times. The problem is that it is hard for me to incorporate more than 3 swimming sessions a week. So I started thinking about dry land exercises. I thought about running in order to improve my cardio, and gym training in order to improve my power and speed. But I find it hard to find reliable and relevant information on which exercises or technics to use. Most resources I find are designed for young competitive swimmers. I'm really not there. For example, I don't need exercises to improve my exit from the blocks. That is the least of my problems. I encountered some resources which state that Crossfit is a good match for swimmers. But again, some other resources dispute that. I would appreciate of someone can share or recommend from his personal experience. Thanks !