Music Theory Questions

Just bought the Hooktheory books and reading through them. I have some questions:

  1. Are chords played on the piano (or strummed on the guitar) on each beat? If the I chord is the entire first bar, and there’s 4 beats in the bar, do you play/strum the I chord just once on the first beat, or do you play/strum it on each beat (4 times in a bar)? (for example, the chord progression “I vi V IV” would actually look like “I I I I vi vi vi vi V V V V IV IV IV IV” ?)

  2. It’s hard for me to find/count the pulse / beat of a song if there are melodic notes off the beats. My brain tends to count the melodic rhythm instead of the beat. For example, in this progression: https://www.hooktheory.com/hookpad/view/ROmNeDbjoNw , I count along with the melody (one…, 2, three…, 4, 5, 6) instead of the beat which should be 1, 2, 3, 4. Any tips on how to find/count/stay with the beat?