If i realized that I didn’t daven mincha yet right after shkia do i daven right then or daven 2 maariv’s?
It depends where you are. In europe and the U.S.A. you can still daven, however in Eretz Yisroel you would daven a double maariv.
M:B 233-14, Eishie Yisroel 27 ftnt. 14 in the name of R’ C. Kanievsky shlit”a that what the M:B says that B’shas hadechak that one can be leneint is specifically in Europe (and the States), but not in E. Yisroel, (since the sun sets much faster over there).