May someone Briefly explain Capital Gain Taxes

I own a home in Central Florida near Orlando, and have lived there for 5 years. This year I rented out that home and moved to Southwest Florida where I am currently renting. I plan on selling the house in Central Florida. Will I have to pay capital gains tax on the profits I make on the home? If so, how much? 20 percent? If i decide to keep renting that house out and purchase another home where I am currently now, will I have to pay capital gains on profits made on the second home if/when i sell it? Any and all answers are appreciated.