Don't be surprised if you get a number of posts deriding your purchase of a Wal Mart bike.
But, I congratulate you on your move forward into biking. I hope you get hooked, and it will not be long before you consider the purchase of a good quality used or new bike (such as an entry level mtn bike) for about $300.
Keep pedaling. Don't spend another dime on that bike, but instead save your pennies for your upgraded bike.
You will be amazed at the difference.