Miracles, signs, and wonders
The Church dogmatically defines only one miracle: that Jesus rose from the dead. That is the cornerstone of Christianity. If He did rise from the dead, that suggests that all of the other miracles attributed to Him in the New Testament and in the history of the Church are possible in principle; if He did not rise from the dead, we are still dead in our sins and it does not matter to us whether any of the other miracles attributed to Him really happened.
We are saved by the death and resurrection of Jesus, which the apostles witnessed. The Church is built on the foundation of the apostles. We have no time machine that will allow us to see Jesus' death and resurrection for ourselves so that we can evaluate the apostolic tradition objectively. Nor is Jesus volunteering to live in a Resurrection laboratory where anyone who wants to verify His resurrection for themselves can kill Him and watch to see that He Himself rises from the dead; one offering of Himself on the Cross was sufficient for all sinful human beings at all times and in all places.
Either we take the word of the apostles about the miracle of our salvation or we don't. There are no other choices.
Crossing the Red Sea
The Bible gives conflicting accounts of the crossing of the Red Sea. One of them says, "Then Moses stretched out his hand over the sea, and the LORD swept the sea with a strong east wind throughout the night and so turned it into dry land" (Ex 14:21). The other account says that the waters split into two: "But the Israelites had marched on dry land through the midst of the sea, with the water like a wall to their right and to their left" (Ex 14:29).
We are not saved by the Red Sea miracle. I don't care which story is historically correct.