Looking to start swimming

Hello USMS forum, First off I just want to say that it is great to be here and that I am really looking forward to speaking with you all. In my younger days, everyone would get togeather and go down to the local swimming pool and play around for hours. These days I haven't seen a pool for about 4 years. As a teenager and in my early twenty's, I always had a slim figure but as the years have gone by my stomach has begun to grow. So, it's about time I did something about it! Then swimming came to mind. So the main question is how much do I have to swim? for it have an effect on my weight and health? I think the local swimming pool is 25 or 50m in length, as I said it's been a while. I purely want to do this to get a little exercise back into my life. I see there are a few group exercise sections but I'm not too comfortable in a group but I am quite happy swimming on my own. I have my fashionable swimming truinks from this site here: www.easyprices.com/.../swim-trunks-price haha, and goggles ready to go. If there are some health and exercise specialist on here I will place a few details below that might help you know how much exercise would benefit me. Age: 32 Height: 6ft Weight: 82kg Daily exercise: 0 Job: Sitting in an office As you can see I haven't got the healthiest lifestyle and it could do with a few adjustments. I'm looking forward to some replies and seeing how beneficial swimming can be!! Thanks guys www.lobsc.org.uk/.../cust_bg_2504_1438822456879.jpg