A sporting goods store is obviously a retail business. Your main issue in trying to write a business description is working out a solid business plan that would convincingly show a prospective investor that you would be likely to be profitable. To do this, the first thing you would need to do is show that there is a genuine need for your products.
Demonstrating need means two things. First, there need to be people who want to buy your product. If you are considering a bricks and mortar shop, this means potential buyers within a limited driving distance. For an internet shop, you eliminate the geographical limits on your potential buyers, but you also end up in competition with every other online sporting goods seller.
Next, you need to define your specific market segment and how it is positioned against the competition. For example, if you want to open a generic shop competing on cost, you will be trying to go head to head against places like Walmart, which can get much better deals from wholesalers than you can. If you are looking at a niche market, such as handcrafted canoes or teaming with artists to make unique snowboard and skateboard art, you have a more limited market but less competition. Another possibility is second-hand sporting goods which is a small but thriving local market with fewer fixed costs, as you can take goods on consignment and earn a profit on a percentage of sales, rather than having to invest in building inventory.
Next, you need a financial plan that breaks down your costs in some detail, and analyzes the sales volume you would need to make a profit.