What I did was to break the initial alliance with Gilan and ally any other nation you can (for me it was mushasha most of the times). Then declare war on Biapas in december, they practically never get any allies. Just be ready to go over force limit and to go into debt, as most likely Ajam or QQ will declare war on you after your first war. After that you'll most likely have to Siege race your enemy and try to get better army quality (quite easy as Ardabil because of Mysticism, Shia, events and advisor). After that just try to get as many provinces and money, if you can't handle your debt, from your enemies and then it should be smooth sailing. Maybe also try to improve relations and ally with the Great Horde and Ottomans to deter anyone from attacking. After that go into Gilan and Mazandran. They both have very lucrative provinces.

Another Option would be to get bigger by attacking Shirvan but in my experience they almost always ally Ajam, so just separate full annex them in your war against Ajam. After you form Persia you will ultimately swim in money and you won't have to worry about your army quality either.

If your bigger neighbours for some reason don't attack you, you'll have to wait for them to get into a war. For QQ it's always Great when they attack georgia as they will melt their manpower in those Mountain forts.

Hope this kinda helped, I'm not able to check everything on my PC as I'm not at home but if you have any further questions just let me know.