Game is extremely buggy + Audio stuttering?

Hi! I'm really new to this game so sorry if this is just kind of an issue with the MoP version in general - but I've noticed the game is really, really bugged out? I just started playing with a pandaren character, I've only gotten to the quest where you meet the leader of the Horde and you're supposed to follow him to the Valley of Honor. I've noticed a looot of bugs and wanted to know if there's anyway to fix this on my end or if this is just a problem with the game?

The bugs I've noted are;

Characters get really bugged out at cutscenes or don't follow the coded actions they're supposed to. NPCs will talk over each other and straight up not say their lines at all, there's this bug I've noticed where instead of moving from their space - example when you're supposed to follow them somewhere - the model duplicates and stays in one place, or just doesn't act like they're supposed to. I'm not sure since I've actually never played Warcraft before now - but I'm pretty sure the Master pandaren's death speech wasn't supposed to end in him making a really loud, comical death noise and collapsing. The scene where you and Ji Firepaw go and meet the leader of the Horde, Ji Firepaw wasn't in the room or cutscene at all.

I'm currently still on the quest where you have to follow the Horde leader to meet him at the Valley of Honor - I looked up a tutorial because I couldn't find thim there and found he wasn't in the location he's supposed to show up. I haven't played anymore than that for now but I'm hoping he may still be at the starting location and I can finish the quest that way. Because otherwise I'm stuck :(

Also! Audio stuttering is another thing I'm having a huge issue with - I have my audio quality turned on as low as it can go and it still stutters a lot. I've never had this bad audio stuttering in any other game I've played so it must be on this one and not my speakers/headphones.

I also do have my graphics, settings, etc turned down way low to see if it fixes the bugginess and it hasn't.

Thanks if anyone can figure out how to fix this!