When playing bass chords do i hit all the notes within that chord ? and i don't mean arpeggios .?

AM7= A major seventh 1,3,5,7 do i hit all these notes at the same time or can i use A and the 3rd and drop the 5th and add another note from another chord to creat a harmony ? also is A3 an A note with the C# ? anyhelp i appreciated and i don't have a teacher i learned everything so far on my own and through help from other bassplayers and studying scales and constructions chords and intervals , anyway i just need help within this area with the chords .