Ytdyklly

I belong to a Christian family but I could never accept the fact that God can incarnate as a human. But I do not follow all 613 commandments either. I guess nobody can. I only follow Noahide commandments and never broke them.

Is that enough for a Gentile to be saved?

Judaism doesn't have a notion of "being saved". What we know is what is required of a righteous gentile. The Rambam (one of the greatest codifiers of Jewish law) writes explicitly (Mishne Torah Hilchot Melachim 8:11) that

Anyone who accepts upon himself and carefully observes the Seven
Commandments is of the Righteous of the Nations of the World and has a
portion in the World to Come. This is as long as he accepts and
performs them because (he truly believes that) it was the Holy One,
Blessed Be He, Who commanded them in the Torah, and that is was
through Moses our Teacher we were informed that the Sons of Noah had
already been commanded to observe them.

So a Gentile who never broke the Noahide commandments for the right reasons has a portion in the World to Come.

Also, and for information, not all 613 commandments apply nowadays that we don't have a Temple. R Isaiah Horowitz (the Shelah) counted there are only 369 commandments applicable today, and some only apply to specific classes of individuals (e.g., Kohanim or Leviim, men or women) or in unique circumstances (e.g., building a house). As a result there are "only" 270 mitzvot "that every Jew is required to observe, without any particular circumstance ever having to come about" (see here for more details).

In Judaism, there are several core figures that Yahweh makes covenants with:

Noah

Then God blessed Noah and his sons, saying to them, “Be fruitful and increase in number and fill the earth. The fear and dread of you will fall on all the beasts of the earth, and on all the birds in the sky, on every creature that moves along the ground, and on all the fish in the sea; they are given into your hands. Everything that lives and moves about will be food for you. Just as I gave you the green plants, I now give you everything. “But you must not eat meat that has its lifeblood still in it. And for your lifeblood I will surely demand an accounting. I will demand an accounting from every animal. And from each human being, too, I will demand an accounting for the life of another human being. “Whoever sheds human blood, by humans shall their blood be shed; for in the image of God has God made mankind.[Genesis 9: 1-6]

[New International Version (NIV)]

Abraham

I will establish my covenant as an everlasting covenant between me and you and your descendants after you for the generations to come, to be your God and the God of your descendants after you. [Genesis 17:7]

Moses

Then Moses went up to God, and the Lord called to him from the mountain and said, “This is what you are to say to the descendants of Jacob and what you are to tell the people of Israel: ‘You yourselves have seen what I did to Egypt, and how I carried you on eagles’ wings and brought you to myself. Now if you obey me fully and keep my covenant, then out of all nations you will be my treasured possession. [Exodus 19:3-5]

The Noahide covenant was with Noah and his descendants. The Abrahamic covenant was with Abraham and his descendants. The Mosaic covenant was with the descendants of Jacob. Since, in the Judaic tradition, everyone is descended from Noah, his covenant applies to everyone. The Abrahamic and Mosaic covenants are taken to apply only to Jews.

There was also a covenant with Adam, which Adam broke, which in many Christian traditions is taken to represent the Original Sin that people must be "saved" from, but that concept does not exist in traditional Judaism.