Mamy if you are talking about digging a little seedling go for it, a small pot is good for starters.
Now the part that will make you think. You say the 11" maybe not the 1st choice, but typically a small tree is cut down from a bigger tree. In many cases we take a 15' tree, yes foot, and cut it down to maybe 12" yes thats inches, then grow the branches we need, I realize this sounds next to insane for what we do but it is the typical path. Now mind you the trees don't need to grow 15' tall first, but the "normal method is to let a tree grow( puts girth on the trunk) cut it back(called by many the Chinese hack back ) then grow out some more, then hack again, as required for the tree we want.
I am thinking that this makes no sense to you at this point, on purpose almost, not to confuse you but to give you some plain basic info so you can do a little homework with somethings to find out about. I do this so you get more info on bonsai, the whys and hows, if for no other reason than to let you see how involved bonsai can be.
Now your seedling route will take quite sometime before you are actually practicing bonsai, in the mean time grab a home depot juniper, or if luck enough to have a bonsai nursery close by then by all means stop and ask them about starter materials, these will give you something to work on and gain some experiance. But I still suggest do a bunch of reading about our "hobby" and welcome to the insanity.