Extra lighting is not needed from what you have described. Don't worry about getting extra lights. Just make sure the water temperature is more or less 82 degrees. Also, since you have a 2 gallon only, make sure you do one 50% water change halfway through the week and then a final 100% at the end of the week, or you can just do a 100% at the end of the week. Make sure you add water conditioner to your new water because it will contain chemicals from your tap that maybe fatal for your betta. Feed 4 pellets max a day. Have fun
Sorry for giving you more info than needed. It's just that so many college students are starting to buy a betta nowadays and I just want the owner and the fish to have a successful life.