I've been on PrEP both long term and short term.
When I first began taking it, I felt nauseous in the morning time and would frequently throw up bile for a few hours after waking up (imo, eating a bit helps to calm this down). This was the only real side effect I had. After about a week, I no longer had any issue.
The official advice is to take it around mealtime as this will reduce nausea, which I have found to be true. A lot of nurses recommend taking the pill every night before you sleep as this may allow you to "sleep off" the negative side effects - I found this NOT to be the case. Taking the pill at night only made me more sick in the morning whereas taking the pill in the morning or daytime would drastically reduce nausea. I don't believe PrEP has any interactions with common over-the-counter anti-nausea medications, though I can't attest to how effective these would be in curbing some side effects personally.
Also if you'd prefer, you can dissolve PrEP in water, grape or orange juice and drink it that way. Hope this helps!