Advice please...

I like to do my strength training before endurance but I've been doing strength training for a while now. If you're just starting, do it after your swim training because your muscles could be too fatigued for your swim. 

Select one from the following:

Upper body press: bench press, overhead press.

Upper body pull: pulldowns, rows, pullups if you can do them.

Lower body: squat, lunge variation, deadlift variation.

Abs: Your choice.

The above are known as compound lifts and should form the basis of your routine. If you have the time, energy, and desire to do more, by all means do so. But compound lifts are "compound" because they involve several muscle groups. For instance, when you do a press, you involve your triceps along with shoulder and/or chest muscles so there is really no need to do an additional exercise for your triceps. If you want to, great, but there really is no reason for it.

Avoid the leg extension because it is not good for the knees. If you feel you must do leg extensions, use a lighter weight for higher reps (like 20 reps). Leg curls are okay, though. If you're not sure how to squat or deadlift properly, stick to lunges. Single-leg work is very good.

If you're just starting out, start with 2-3 sets of 8-10 reps. Later, we'll give you something more challenging.

What's the one key thing that boys have that girls don't? No, it's not what you're thinking. Answer: Testosterone. The hormone that's responsible for large muscles. A close second is caloric intake, and as you said, you're cutting calories. Having said that, as a beginner, you may notice some slight gain in muscle size even in a caloric deficit. These are "newbie gains" and they won't last forever. In fact, they won't last long at all.  Look, there's a reason why professional bodybuilders and many recreational ones take steroids - gaining muscle mass is hard to do, even for us guys. There is no danger of you getting too bulky. And if for some strange reason you gain too much muscle, just stop lifting weights, keep doing your endurance training, and stay low in the calories and the muscle will go away before you know it. But I doubt you'll need to worry about that.

I agree with Mike the Bear almost wholeheartedly. The only thing that I vary on slightly is that I personally believe that deadlifts and squats should be incorporated on a regular basis, even together in the same weight session. Different variations of squats and deadlifts can be used, but they are both fantastic lifts for many different parts of the body. You'll want to slowly work into it so that your body can adapt.

While you're cutting calories, you won't bulk up. You need to take in more calories than normal to really be able to bulk up at all. So, provided you're eating enough only to maintain weight or even cut weight, you won't bulk, you'll just tone up while slimming out.

Hope that helps!

some good advice for sure ... only thing that I really differ on is the leg extension

1st: I don't normally do them but that's more because of time constraints than anything else --- I live by the K.I.S.S. philosophy in the gym ...... 2 days per week, 2 sets of the same exercise per body part --- so I try to use more compound movements [bench press, squats, etc] ... and I will try to shake up my routine every 3-4 months to keep my body guessing ... also helps you stay mentally into it and not get bored doing the same things over and over

if I am going to do 2 sets for the legs and I can only use 1 exercise I will do squats ... I truly believe that it is the single best exercise you can do and helps your entire body develop muscle [studies have proven this] --- so there's just not room for leg extensions

HOWEVER, if you found yourself on the road staying at a hotel and they have a limited gym with a leg extension machine, it's better than nothing ----- just DO NOT EXTEND THE FULL RANGE OF MOTION [90 degrees] ....... only go about 4/5 of the way and they are a fine exercise because it keeps the resistance on the quads

hope this helps