Basically the meaning it's the same, grammatically there are very subtle nuances that even native speakers don't know but use them incounsiously, for instance it's more common to say: "Vieni qui" of "vieni qua" "sono qui" than "sono qua", but it could also vary depending on the italian region of the speaker. I think you should not worry much, there is no problem of comprehension so you just can pay attention when you read. Following an useful resource about this: https://affrescodellalinguaitaliana.com/2016/09/28/qui-e-qua-qual-e-la-differenza/

Yes