at first, initially

[alan gould]

are all the following used?  in english "a priori" is reserved for only a small % of highly educated:

a priori

à première vue – at first sight

au début – at first, in the beginning

au premier abord – at first sight, initially

[Chantal Savignat]

a priori

à première vue – at first sight

au début – at first, in the beginning

au premier abord – at first sight, initially

=> Yes these 4 are used.

the first two and the last one are used by educated too, but I think, by a bigger % of educated not just highly educated.

it's not a popular way to say that but everybody hears this commonly.

the third is used by everyone.