Background:
I am 33 y.o. about 1.77 (which is like 5'10in) around 200-205 lbs. According to BMI measurements I am overweight but in reality I have a big frame, broad shoulders and compact built, fairly athletic but perhaps not fully fit. According to my impedance scale (which are not entirely reliable by default) body fat index around 20-21%.

I am at the gym 3-5 times a week, combined with basketball, soccer and squash depending on scheduling. I bike to work and back 30-45 mins every day. What I am trying to get to is that I do have a fairly active lifestyle, despite being in front of a computer all day. 

I have started noticing that while I notice improvements on the appearance (bigger arms etc) I am not really getting stronger, in the sense that I can't really do more pull-ups than before, just to give an example. I haven't been able to make much progress in terms of weights in bench press, squats etc. 

My main goal for the workout (besides being healthier) is to shed the extra weight, to get better into better shape so that I strain my joints less when I do ball sports. I don't really need to bulk up as I am fairly heavy-set by default, but I don't want to lose any strength by focusing solely on cardio training.

Given the goal of shedding the weight without losing any muscle strength, and the fact that I am not making much quantitative progress, do I need to take supplements like BCAA or creatine etc to make sure I am not burning through the muscles throughout the workouts? I see people taking pre-work out shakes or some suspiciously colorful stuff during the workouts. What is that about?