I would read them all!, especially in the case that I am sometimes bored. 

The next poster would get a house, for free! 

I would spend all the money I'd saved for a house on adding secret passages and hidden trapdoors! 

The next poster would find an anonymous letter asking them to meet the mysterious sender in a nearby parking lot...at midnight.

I would be creeped but I would go with someone to see what is it

The next poster would get u bunch of blankets in SUMMER 

(I don't like summer at all)

I'd give them to a charity that would distribute them to people in need of warm blankets, like the homeless or refugees or people hit by a disaster.

The next person gets to trade places with a favourite famous person of their choice (from any era), just for one day!

I would switch places with the Royal Family in England! (It's not every day that you get to pretend to be royalty) 

The Next person would get to travel into their favorite videogame and play the game as one of the characters in the game!

Well, I'd be in the post-apocalyptic future of Horizon Zero Dawn. I guess getting to really be as Aloy could be fun. (If I got to keep my knowledge of the present day, though - I'd probably just spend most of my time talking to the other characters and explaining all of the history they've forgotten.)

The next person finds a genie, who will let them visit one historical event (but not change anything).

I would go back to the signing of the Magna Carta in 1215, just so I could admire the medieval armor and weapons present and also laugh at the look on King John's face when he finds out he has to sign some of his powers away.  

The next person gets their choice of any kind of water vehicle for free!

I would get a surfboard, and if I ever go on vacation to a beach with nice waves I’d pull it out of storage and surf the whole day

The next poster has to pick to teach a class they have no knowledge in (they’d be bluffing really well the entire time)

I would choose English (or ELA) ! Seems fair enough, considering you don't have to know history (Social studies), or remember mathematical figures (way too hard!) or study astronomy (which I barely know anything about). 

The next poster would get to grow any fruit or vegetable in their garden, but the best part is it only takes 2 minutes to grow and produce!

Pineapples. I love pineapples. And this means no more sub-standard ones that have had to be transported unripe and put in cool storage before they're sold — let alone tinned ones.

The next poster instantly gets to be a champion player of any sport of their choice.

Oooh. I'd probably choose ice skating, I guess?

The next poster wins a year-long supply of fresh bread from a nearby bakery.

Yes! I love to make bread recipes. Especially garlic bread! And of course I'd thank the baker. 

The next poster has the power of Invisibility! 

I would use that power if I ever did something embarassing and I wanted to diseper.

The next poster would have get a delivery box with a thousound cats inside!

I would keep just the two or three that I got along best with and sell or give away the others — only to good homes, of course. I love cats, but unfortunately I don't currently have the time, the space or the money to become the world's greatest Crazy Cat Lady.  

The next poster is given an airline ticket to a mystery destination! (Guaranteed COVID free.)