Hello dsfargeg,
First off, welcome and thank you for posting your map. I must say that I really enjoy the watercolor aesthetic.
I'm going to focus on the fonts, since that was a concern of yours. It is perfectly acceptable to use multiple fonts on a map design. However, I would say that you probably shouldn't be using more than three before they will start to detract from your work.
The key is that the fonts compliment one another. The only way to truly tell if the fonts are complimentary is to play with them. I often open a blank Word document and type several fonts and look for those that look good together. There are also websites that list complimentary fonts if you Google the term. The only disadvantage with that method is that the fonts are often rather bland and might not be as dynamic as you'd like.
Personally, I think the font you're using is too ornate for even the larger countries. Even zoomed into your painting, I had trouble discerning the names. If you're absolutely set on that particular font, I would suggest playing with both the size and the shape of the text so that there is as little overlap with the other map elements as possible.
For example, currently 'Tembarga Country' at the bottom of your map could use a slightly smaller font size so that the T doesn't overlay the river and on the mountain. The word, 'Country' could be adjusted so that the Y doesn't end on a river. That might help make the font more readable for your players. There are plenty of areas when the font can be resized, curved, or spaced more effectively so that the letters land upon the clean, parchment background instead of on the actual terrain elements. It will also help make the map less cluttered looking.
But when it comes to the smaller writing you definitely need to change the font. Areas like 'ashcroft' and 'Midwood' can barely be read even zoomed as far in as possible.
If you want a suggestion regarding complimentary fonts, I would try Bridgnorth for the larger text. It gives a similar vibe as your current choice and is much more legible. For the smaller font, I'd try Footlight MT Light. Again, it gives off a similar feeling and is easier to read.
Those are just suggestions. Take what you need and flush the rest. Good luck with your map. I look forward to seeing how it progresses.
Regards,
Scott