If the PH reads 7.6, then go to the HIgh PH bottle and use that to see what the PH is. If it's higher than 7.6 then normal PH test won't read it.
Also shake all of the bottles for at least a few seconds before using them (I tap them on my palm a few times too). I find that not doing so can cause inaccurate readings if the liquids inside settle too much. For the nitrate test, you want to shake and bang both bottles on a hard surface for 30 seconds and then vigorously shake the tube for 60 seconds and then wait 5 minutes for the results (it can be inaccurate if not done exactly as there's a reagent powder in the bottle that can get clumped an cause inaccurate readings) although you probably won't have nitrates yet.
It's good if you don't have ammonia, that means you're staying on top of water changes. But to double check I'd shake the bottles and test again.
Your PH is likely fine btw, just use the high PH kit too so we'll know what it reads.