Finding a Tarot deck is very easy. Bookstores, New Age stores and the internet make it easy to find the cards. Choosing the deck that is right for you is another story.
Searching the internet is a good start and you will find many decks. I would suggest that once you have searched, head to a bookstore that has samples on display. Books A Million has cards on display. Look at the imagery and feel the cards. Decks come in different sizes. You will want to see which size card is most comfortable to handle. There are beginner decks with meanings printed on the cards.
Don't let anyone tell you that you must start with a certain deck. It is a personal choice. Tarot decks have 78 cards. Oracle decks or Spirit decks may have less cards and the meanings of the cards may be very different from the Tarot. You may want to start with a true Tarot deck, but once again it is your choice.
Pick a deck that feels comfortable to you. When you hold the deck do you feel anything? If you are more visual it will just be the imagery that strikes you. Over time you may acquire many decks.
Go ahead, begin your journey.