Count and listen
Clap a steady four-beat pulse while saying 1-and-2-and-3-and-4-and. Listen to a song and find its regular beat. Sing a short public-domain melody and notice whether each next pitch rises or falls.
Map the neck on paper
Draw six lines for E A D G B E and write note names for frets 0 through 5. Check your answers later with the interactive fretboard. Imagine a familiar chord change, then practise the movement on a real guitar when you can.
Can this replace playing?
No. It helps with timing and note knowledge, but you need the instrument to practise finger placement and sound.