It is a scrapbooking card. The ones you add to photo albums.,It's on a card. Is it a sentence? Usually sentences are not on cards. Why would a sentence be on a card?
Normally cards have names. So post 3 makes the most sense: this is a business card from a business
whose name is "Let's Go! Travel".
There are countless uses of English words that are NOT sentences, and therefore do NOT follow grammar rules:
book titles, article titles, headers, slogans, banners, cards, names, chants, songs, T-shirts, posters, signs, list items...the list is long.