Is your unit a Mono or Stereo deck?
LOOK at the HEAD,
https://www.petervis.com/Cassette_Tape_Recorders/sony-tc-330/reel-to-reel-track-formats.html
2 track (mono or stereo) is two wide stripes on the head, centered.
a. mono, 1 track one direction, flip tape over, play that track, i.e. dictation, record lectures etc.
b. two track stereo, one direction only.
Four Track is 4 narrow stripes on the head.. commercial pre-recorded four track tapes: one direction uses tracks 1 and 3 for two track stereo. flip it over, now uses tracks 2 and 4 for two track stereo.
you can have extra heads (6) and reverse play without flipping the tape, often 6 auto reverse.
Four Track Forward, musicians deck to record individual tracks, i.e. add vocal later, add drums later. head looks like 4 narrow tracks, but all 4 are individual tracks, one direction only. 4 meters show each track.