I have the Rift S, inside out tracking from the headset is handy. I've only ever encountered problems with it a handful of times. Most times when I put my headset away it forgets my guardian settings or just can't recognize the room, so I've got to re-draw my boundaries and set the height again. It's not that big of a hassle to be honest. Another benefit is that you have black&white cameras for easy peaks into your room to see where you are.
It only has like 180 degrees of tracking but it lets you play every game out there just fine. Just try not to reach for anything too close to your back as you'll start to lose tracking. It does do a pretty good job of estimating where you're trying to reach whenever it can't track you though. Messing around with bows in Blade & Sorcery requires you to reach behind your head for additional arrows, but tracking works perfectly fine. You start to lose tracking whenever you put your controllers close behind another where one is out of your own view, holding them together as if you're holding a pistol works perfectly.
The built-in speakers are pretty good IMO. You can always use a headset with the rift though but I lack one with long enough cables or is wireless so I've not bothered. The headset also has a microphone, obviously, which is decent quality. I think this goes for most headsets actually, I've only ever had the Rift S so I wouldn't know.
I recommend you take it easy when you start out in VR, if you start to feel motion sick or anything, take a break or stop for the day, then continue. I decided to power through it and keep playing like an absolute idiot, I couldn't actually enjoy the games I played because I was constantly sick, not to mention using smooth locomotion which threw me off completely. So stopping when you feel motion sick in any capacity and continuing the next day is highly recommended. I ended up feeling sick just thinking of VR before HL:A was released, after it did release though I got back into it and stopped once I felt sick, then continued the day after. It got far better and I stopped feeling sick just thinking of it just because I did it like I described.
I trust you understand, or already knew though.
P.S: Play HL:A, it's a brilliant experience.