"At first" refers to the preliminary or initial stage of something. Synonyms for "at first" include "initially," "at the outset," "in the beginning," "primarily," "firstly," "in the early stages," "to start with," "at the beginning," "before anything else," "in the opening phase," "preliminarily," "to begin with," "in the commencement," "to start off with," and "to kick things off." These synonyms can be used interchangeably in sentences to enhance readability and style. They can also be used to give emphasis to the start of a process and denote the advancement of something which is about to happen.