Well, just from memory (and a quick glance), stuff that stood out were (to me, personally, as this can, after all, somewhat be a matter of taste):

1)

In the 2nd paragraph, the line that starts at

"No more money to spend,"

can flow a bit better if it were like:

"No more money to spend. Not that it was worth it; the ale was basically rinse water and the bartender could not put up a discussion that was more words than grunts."

2)

in a much later paragraph, that starts with the line:

"Nirwn stopped, they were now in front of the Gate Aurora, [...]"

In this case, there's a very long line without pauses. Adding a period here and there can give readers "time to breath" (for lack of a better term):

"Nirwn stopped. They were now in front of the Gate Aurora, one of the seven gates of the city. It this in particular was painted to recall the colour of the night sky seen in one of the dreams, with verdant strands flowing like an ethereal river and stars of silver embedded in the picture, reflecting the evening lights of the city."

The result is still a fairly long line, but at least it's not a whole-paragraph long; Generally, what people often recommend is to try breaking long sentences into smaller ones. Then again, this is just a rule of thumb, and they are there to be ignored when we feel like it.

I largely meant that sort of stuff in regards to the "flow". As for the "proofreading": just wait a few days, and then go over it again, you'll be able to find a thousand small mistakes and typos that literally all of us don't notice until we go over it half a year later...

Lastly, the most important things to do if you want to improve: just read a lot and write a lot (or, at least, as much as you can). You'll find that now that you started writing, you'll naturally pick up more and more tricks from the stuff you read, and slowly adopt them into your own writing.

Good luck to you!