With tennis, you can’t always expect to have the best weather conditions. If you want to play tournaments or even be a professional tennis player, then you’re going to have to try playing under different conditions, The more you play, the more you’ll get used to it.

So don’t feel bad about your first few matches on the outside courts. You can’t expect to play your best under different conditions for the first time. Like I said, play in outdoor courts more often and eventually you’ll get used to it.
References :

First – make a tally of what your club needs – equipment, uniforms, floor space, rent, electric, heating / ac, water, phones, computer, employee salaries, & printing / laminating. These decisions are yours, so I can’t really guide you as to how big or small the estimate will be. However, once you know, you can find out the prices for equipment by checking out a wholesale site like http://www.net2fitness.com.

Also think about an advertising / marketing budget.

Now think about how long it will take for you to make a profit, and start paying back your loan. You need to have at least 1-2 years operating expenses saved to be safe.

Add it all up, add 2.5% for inflation.
References :

Try to play outdoors more, that way you can make up for the wind, and when you play indoors you won’t have to take that into your calculations.
References :
Tennis experience.