God can, of course, do anything that He wants to do. In this case, however, He chose to use the Catholic church as His messenger. The Holy spirit inspired the early Catholics and thus they became His servants. They are no more special than anyone else, just happen to be His chosen group for that task.
As for your second question, there were no gospels, as such, before there were catholics. St Peter and the rest of the Apostles became known as Catholic and it was that group that wrote, transcribed, copied, edited, etc etc etc what we know as new testament scripture. Before the Apostles there were no Gospels and the Apostles were the first Catholics...
As for the "gospel" and your erroneous comment that there was no gospel before there were catholics (I noticed you slipped in the lower case "c"), I wonder how it was that Abraham and other Old Testament saints were saved without believing the gospel? Are you familiar with the prophet Isaiah? See if you can identify the "gospel" (the good news) in this verse:
But...just in case you are making the same mistake I see many RCs make over the word "gospel" insisting the word only means the story of Jesus Christ and His teachings as written in Matthew, Mark, Luke and John, even that is NOT something Roman Catholics today can claim is all theirs. God used "holy men" who were carried along by the Holy Spirit to write the inspired words they did and man can lay NO claim or credit for that. It is ALL a gift from God. RCs claiming credit for the gospel are like the rooster thinking his crowing was what caused the sun to rise.
Likewise...
ROME can, of course, say anything that it wants to about what things GOD COULD have done.
And by saying so; makes it GOSPEL that they WERE done!
https://www.youtube.com/watch?v=04854XqcfCY