I've been sort of "all over the place." I always liked weights and several years ago I tried learning the Olympic lifts. Without bumper plates and a coach telling me how exactly to fix the many flaws that come from being self taught, I was not good. Then my wife got into triathlons and I joined in. Did a few sprint distance tris and a half-marathon. Then a local Crossfit got an Olympic coach and I joined his weightlifting club (I'm still a member). However, I have a seriously messed up back, and despite having surgery two years ago for a herniated disk, it is still messed up. Also, I'm fat as hell. I've decided to take a break from the heavy lifting and get back into doing some endurance training and kettlebell lifting. Now that you are familiar with my training background, here are my thoughts:
If you ask about weight training on an endurance or triathlon site, you may as well start a discussion about religion and politics. There are some diehard endurance who will vehemently argue that weight training has zero impact on endurance performance.
Despite the above, most canned/free triathlon training programs have two weight training days. But the exercises are lame.
You mentioned that you are learning how to swim. For now, focus all of your time and energy on that. Trust me. All triathletes, except maybe those who swam competitively in high school and beyond, hate the swim. Swimming is very technique driven. It's one thing to know how to swim so you don't drown, it's a whole other thing to be a fast and efficient swimmer. I learned how to swim "so I wouldn't drown" as a kid. I am comfortable in the water and have no fear of drowning. But my 16 year old daughter who has been swimming competitively since age 8 can kick my ass at any distance. She actually coaches me on my swimming technique. She's a tough coach, too.
You asked about the Olympic lifts. Having competed as a masters lifter I love the lifts. But... First, if you don't already know how to do the lifts, save learning them for later. You're already trying to learn to swim and you need to focus on the swim. If you can do the lifts with some proficiency they make a good addition to tri training. Endurance events are really about power endurance, especially the bike, so it is not a bad idea to improve top end power. However, I have found that kettlebell swings and snatches are better because these are done for high reps and actually improve power endurance and conditioning.
In an effort to find the "best" strength program to add to tri training I've read studies and articles on the subject. There is no best program. The articles suggest that strength training helps endurance sports because it allows the muscles to work more efficiently. Not what I expected. So, my philosophy is that I continue to train with weights because I like to and because I believe that strength is an important component of general fitness. I no longer care whether it helps or hurts my endurance performance. I will do it anyway.
As I said, the weight training recommendations that come with most tri plans are lame. You don't need to waste time on biceps curls and leg extensions. Well, maybe some curls so you'll look good in your tri suit. I stick to the big exercises and follow Wendler's 5/3/1 plan. I don't try to get cute and do sports specific exercises in the weight room. I keep those "sports specific." For instance, if you want to get stronger on the bike, push a big gear up a big hill. Repeat.