how much weight should I lose, or should I at all..?

I’m 74kg / 163 pounds, 179cm (5 feet 10.5).

I’m a male of age 15, and apparently im at a “risk of overweight” according to some bmi calculators.

What should I do to become 60-65kg (132lb - 143lb) in 2-4 months, as that would be considered average weight for my height I guess.

I don’t go outside that much especially rn, since my exams are going on.. I do cycling or swimming like 3-4 times a week tho (for 30 mins-1.5 hours mostly)

Everyone in my age group and height group at my school is 50kg-60kg (110lbs to 132lbs), so im 60 lbs more than average for my region atleast..

Is going to the gym worth it? I recently turned 15 like I mentioned, so I can go there now. (Theres an age restriction at my gym)