Yes, as you know it. Initially when these kinds of things are introduced into the world people are always skeptical about investing in them. But at the end if you are authentic it will always show.

Usually the currencies used in NFT exchanges are in dollars and Ethereum.

Others and some of the most popular are ether and solana.

The second way is by participating in an auction, this method is required to compete with others by offering the highest price and then we can have it and become a private collection.

Yep mostly this method takes a lot of time (I’ve seen 1 month mostly) so this means when you bid someone can even bid higher than you because they will see it. But one nice thing is that as time goes on you can continue to upgrade your current bid till it’s time on the market expires and then it is finally sold.

Doing buying and selling in a trusted market

Yes but getting a trusted market all depends on how well the buyer has done his research. And always remember that the fact that everyone is buying there doesn’t mean that it is a trust worthy project.