America First does not mean that that the USA ought to be first over other countries, dominating them. It means that every country has the right to prefer itself and its own interests over the interests of other countries. This is compatible with respecting other countries' interests and right to self-determination.
So America First has nothing to do with chauvinism which could be characterized as a blind and intemperate patriotism, a belligerent and unjustified belief in the superiority of one's own country. America First expresses an enlightened nationalism which is obviously compatible with a sober recognition of national failings.
An enlightened nationalism is distinct from nativism inasmuch as the former does not rule out immigration. By definition, an immigrant is not a native; but an enlightened American nationalism accepts legal immigrants who accept American values, which of course are not the values of the Left or the values of political Islam.
An enlightened nationalism is not isolationist. What it eschews is a fruitless meddling and over-eager interventionism. It does not rule out certain necessary interventions when they are in our interests and in the interests of our allies.
So America First is not to be confused with chauvinism or nativism or isolationism.
It is also not to be confused with xenophobia. The America Firster has no irrational fear of persons or things foreign. The same holds for every enlightened nationalist.
An enlightened nationalism is not a form of idolatry. 'America First' is not in competition with 'God First.' The principles belong to different orders. The first is a 'horizontal' principle defined over countries; the second is a 'vertical' principle having to do with countries and God. Obviously the following two propositions are logically consistent:
1) Every country has the right to prefer itself and its own interests over the interests of other countries.
2) No country is an appropriate object of worship; only God is worthy of worship.
Finally, an enlightened nationalism is not white-supremacist. I will now quote Rabbi Aryeh Spero, not only because he makes good points, but to distance myself from those Alt-Rightists who are anti-semitic and white-supremacist:
It is not “white supremacism” when people with self-respect display love and admiration for their background and history, wish to defend it, and are proud of it. It is normal and healthy. The opposite is rootlessness. Nor are sincere calls for the maintenance of Western civilization and the Judeo-Christian ethos, as liberals today accuse, “code words for racism”.
The purpose of the shaming we now see coming from liberals against fellow Americans is to muzzle us, so that what we believe is no longer able to be heard or transmitted. It is an enforcement of our political impotence. Longer term, the never-ending demonization is designed to end our civic and religious heritage. Through left-wing bullying and scorn, our heritages are being replaced by the new theologies of progressivism and non-distinctiveness.
That's right; I quibble only with the good rabbi's misuse of 'theology.' Just as progressivism is not a religion, as I have lately argued ad nauseam, it is also not a theology. 'Theology' refers either to God's knowledge of himself, which lies beyond our ken, or to our attempted knowledge of God. But progressivism has no truck with God, being secularist and atheist in its core forms.
You should read all of Rabbi Spero's piece.