Ensure that your each finger corresponds to each fret. In other words, your 1st finger should play the 1st fret, your 2nd finger should play the 2nd fret, 3rd finger the 3rd fret, and 4th finger the 4th fret
Also, when fretting the notes, aim to use your fingertips and not your fingerpads. Right now, it’s easier to do the opposite, but don’t be tempted! You’ll eventually need to use your fingertips once you play the upcoming strings, particularly when playing chords. It’ll get easier to use your fingertips, but only if you start pushing yourself to do so now!