Prophet Muhammad ﷺ said: "The best people are those of my generation (the Saḥābah), then those who will come after them (the next generation: tabi-'een) and then those who will come after them (tabi-tabi'een)." -- authentic hadith from Sahih Bukhari.
The companions include those Muslims who were around the Prophet ﷺ at the time. It includes the men, women and children who accompanied him (SAW). The best of the companions are the four rightly guided caliphs (khulafa rashidoon): Abu Bakr, Umar, Uthmaan and Ali (may Allah SWT be pleased with them all).
The companions played a crucial part in the preservation and spread of Islam. If one reads Islamic history, one will be astonished by how quickly and efficiently Islam spread within a matter of a few years. This success is attributed to the excellent leadership of the khulafa rashidoon.
The companions narrated the ahadith (statements and actions of the Prophet ﷺ) with accuracy. In fact, one of the best hadith scholars was a lady, the Prophet's beloved wife, Ayesha (RA).
The companions' strong moral character is unparalleled and should be an inspiration for us all. They were human, thus not perfect - but we are all imperfect; this is part and parcel of the human condition. Read their stories, read about their lives, the way they corrected themselves, the way they strived to live up to the Prophet's ﷺ message. It will inspire you!