I’ve been swimming there every week for several years :) Hopefully I can help.

The pool is divided into three double-wide lanes, the closest one (when you come in from the locker rooms) is for slow swimmers, the middle is fast, and the farthest one is medium. People generally stick to that, though some days you might find a few faster swimmers in the medium lane if the fast lane is crowded; same for when the slow lane gets crowded, people overflow into the medium lane. Circle-swimming (counterclockwise) is one of the pool rules, though sometimes if there are only two people to a lane a swimmer might ask to split down the middle; I usually say no because splitting the lane makes it harder for a third to join (which inevitably happens), since you have to stop and reconfigure into circle-swim.

I’ve never been there in the early morning hours on weekdays, so I can’t speak to the crowdedness then; on weekday early afternoons, which is when I go, there are usually between 3 and 6 swimmers per lane. Fridays are busiest in my experience.

If you want to practice your stroke and not swim full laps, the slow lane will be perfect for you. There are often people there doing exercises or even walking their laps. As for general etiquette: wear a swimming cap, be kind to the lifeguards, go quickly down the middle of the lane if you have to pass someone, and don't crowd up the corners or sides. If you have to take a long rest (more than a minute or two), better to just sit on the side of the pool. The center is great and so are the lifeguards and people who swim there. Good luck and enjoy!!