I'm normally playing the other direction: sending my English armies to thrash the French, but from what I recall of High...

Flanders & Ile de France are your 2 most important regions, for cash/sea link/Wessex link & troop building respectively. I consider Toulouse a nice-to-have region since it has that CK valour bonus, but you can leave that for the initial few years. Toulouse also provides you with a good sea link to the south and a route into the Iron-rich Iberian peninsular, again you have to survive the initial English & HRE assaults before you can worry about your own conquests. If you can, keep Normandy for the title, I recall it gives +1 Command - I rarely assign titles myself, so I'm not 100% sure on that.

I'd concentrate on keeping Flanders & Ile de France, building inns to recuit mercs to help, and primarily push the English, aiming to cripple or take Wessex, their prime troop building region. Try producing a few emissaries to backdoor the English by bribing armies further north or maybe spies to incite Scotland to revolt - the Scots don't need much of an excuse, they're always revolting.

I recall that Burgundy is a good province, so that should probably be your objective in the war against the HRE. It also provides a land link down to Toulouse. I don't often end up fighting them myself, so hopefulyl others can give you a better pointer for dealing with the Germans.