What kind of motorcycle should i start out with?

I'm 6'3 245 pounds i have little experience with riding and I'm still rookie. I'm going to take a motorcycle safety course before i get a motorcycle. I'm considering buying by friend's 04 honda cbr 600 f4i is that an okay bike for me to start with considering my size and all. I have already rode that bike and i think it is okay but i'm not experienced enough to tell.

You're not going to want to hear this and probably will ignore my advice but here it is anyway. I've been riding for over 50 years and been through just about every imaginable type of weather and situations on my scoots. I owe the fact that I'm still alive to my early years in the dirt. My advise is to buy a dirt bike and really learn how to ride. The skills I learned early have literally saved my life. All the most important skills and knowledge for safe riding on the street are learned best and with less severe consequences in the dirt. You're a big boy but you will be way over your head with a big cc bike. When you do get on the road remember there are no fender benders on a bike, you need to be alert and oriented X10. Start small, start in the dirt, keep the shiny side up.

Any in-line 4 600 is not the best 'learner' bike, their engine and chassis demand to be ridden more aggressively and that is not the best learning technique.
Find a parallel twin 500 or V-twin 650 and go from there.

With a safety course you'll learn the basic's. Just a note, bike only goes as fast as you twist your right hand. Ex: bike can go 150mph, but if you make it go 55 that's how fast it will go. Personally I never ride above 80. That's me. If you want to go faster, I'll see you when I get there.

Defiantly do not get that bike. Since you don't know how to ride do what everyone else does and start of with a 250 either suzuki or kawasaki are the most popular

There's no such thing as a best learning bike. Any bike is just as good as learning on as another bike. I suggest getting a new zx14r or hayabusa turbo.