Looking to take my swim workouts to the next level

I am a 34 yr old male who has been looking to start swimming laps again for fitness over the last few months. My schedule has been hectic, so I'm not able to make it to the pool often, but when I do I'm able to swim a mile with little rest. Since that feels easy for me, I'm ready to ramp things up and make the time to swim a few times a week. My goal is to build up my fitness and stamina so that I can take surf lessons and start surfing, and in general I want to challenge myself and get an adrenaline rush during my swim workouts. I made a couple workouts with breath control and sprint sets that I can do, but I have no idea how much yardage I should be doing now or how much I should build up to. I've read plenty of articles about fitness swimming and looked at plenty of workouts on the internet, but I can't get a good read on how many yards I should swim. 1. How many yards per workout should I aim for right now and also in the next few weeks? Is 1750 enough, or should I be swimming say 2000, 2250 or even 2500 yards per workout right now? 2. In the long run, how many yards per workout should I target? Most of the workouts I've seen for fitness swimmers are at least 3000 yards.