If I'm only slightly overweight and im embarassed to do gym because im embarassed to sweat a lot do ihave a sweating problem or is it just because of myweight im 13 years old 5foot 4inches and 160lbs?

Certainly some people naturally sweat more than others; it's pretty normal to sweat a lot as your body is just getting hot and therefore sweating. Yes, being slightly overweight may contribute to this factor, but you may just naturally sweat more than others.

It's important to try not to get embarrassed (although it may be hard) about stuff like this. If you take exercise easy and try not to get too hot you are likely to not sweat at all. As you are only 13-years-old try not to worry too much about weight and live your life as you want.