Is there any difference between (Neo-Nazism), (White Nationalist), and (MAGA Republicans)?

Nothing except the uniforms.

The following are just a few examples:

Rep. Marjorie Taylor Greene, Rep. Jim Jordan, Newsmax, Elmer Stewart Rhodes III, the Oath Keepers, the Proud Boys, Donald Trump, the Election Deniers, David Duke, Vladimir Putin, Mike Lindell, Rep. Matt Gaetz, One America News Network (OAN), Sean Hannity, Laura Ingraham, Mike Lindell, Michael Thomas Flynn, Rudy Giuliani, Tucker Carlson, QAnon, Steve Bannon. Governor Ron DeSantis, Kari Lake, and Sidney Katherine Powell.

It seems that (Fascism), (Trumpism), (Racism), (Neo-Nazism), and (MAGA-ism)
are all intertwined and they overlap each other.

Here with us, i.e. in the country of origin of Nazism, neo-Nazism stands for the resumption and spread of National Socialist ideas after the Second World War and the end of the Nazi dictatorship.
Representatives of neo-Nazism are called neo-Nazis; the term stands in contrast to "Altnazis" [old Nazis] (also Alt-PG, "old party comrade"), i.e. the bearers of National Socialist ideology who had already advocated it during National Socialist rule, the colloquially known as "Ewiggestrigen" [die hards].

In their basic convictions, neo-Nazis can be equated with the old Nazis.