Don't worry about it. At least you have an idea that it is necessary that you cut down a tree into a bonsai and not grow one up into a bonsai. Even if your idea about a wind swept goes awry the basic stump is intact it will back bud, produce new branching, and perhaps give you some additional ideas as to what should be done.
A major mistake most beginners make is looking through some bonsai books and other visuals as the catalog of bonsai shapes to be utilized in all adventures into bonsai styling. Sadly, branches that grow down like the Procumbens Juniper do not necessarily mean your tree is going to be, or should be a cascade. If you have branches on one side of the tree this does not mean your tree should be a windswept. If you cannot visualize that finished tree with what you have in front of you, you should keep looking until you do.