General rule is at least 1/1000th of viewers are buyers. A youtube videos with hundreds of thousands of views have sold hundreds bikinis.
Companies may give you a product to show off for free or even pay you, but that doesn't make money like selling it.
And as a general rule, each bikini sold nets the affiliate about 10¢. So with 100,000 views, that's ten bucks.
After deducting standard business expenses, travel, food, etc... (since "influencers" almost always have to pay their own way), you make about -$4,000 per trip.
I think this explains why so many "influencers" are riding on their parents' money.
Somewhere between 10 and 100 dollars is not bad for a video that took a day to make in one's bedroom.
Don't know why you're talking about trips. It's never been about traveling. Traveling costs money, it doesn't pay. There are very profitable affiliate schemes for hotels but I doubt they are accessible to a solo teenager and it's nothing like selling a cheap item.