Why wouldn't I take the road less traveled....

Ok...so I am at a crossroads in my life...I guess that is why I am here....people always tell me I would love Europe...and since I am so frustrated with San Francisco....I had to come see....judgment is still out on this city....the people seem so much more my type....but there is still more to learn.....
I have a choice of two very difficult things too do with my life...do I open my restaurant in SF....or do I do something here...the more difficult one would be to do something here....one, would my restaurant idea even work here....maybe I should open a BnB  instead...or somekind of combination of the two....or something completely different...a tour guide business or a wine shop....
I am so late in my life....to think in five years I will be over forty...but most of my friends in SF are forty now....so I do have time....
I could have the option of trying to live here for three or four years...or one or two...our at least until I know plan "make something happen in Paris" is impossible...
There is this big thing about money though...there of only so much of it...and if I use it all up here I might lose my chance to open something up in SF....
The question is...should I be trying to learn French or work on my business plan for when I get back....because the truth is I have to do Paris now....I can't see trying to start from scratch here when I am forty...unless I find a euro partner...but that is a big if I can't count on...
So I guess I answered my question....I should try to learn French....I should try to get a visa....which seems harder then starting a business in  SF...
In any case...i have to do something hard...so far in my life I've only done easy things.