My suggestion is to have at it!!!
You have tons of stuff to learn and you will learn it as you work. (Mostly

)
There isn't really a lot of prep work you can do when you are working with logs..........mostly what you are asking about is done when the sculpture is finished.
Here are some basics to keep in mind (esp when working with pine).
Strip the bark right away.
Checking occurs when the outer shell of the log dries and shrinks around the center which isn't. (drying and shrinking) The small to large cracks or "checks" will radiate to the center of the log......it's called the pith. This won't happen for a while but it will continue for a long time.
White pine cut at this time of year is loaded with water. Once the log is cut, this moisture, combined with hot weather will begin to decay. The early stages of this process will produce what is called "blue stain". It isn't a big deal till it comes to finishing it. That wood is punky and will absorbe paint and stain worse than end grain and will be the first places to rot if it's placed outside.......soooooo, don't cut more than you can use and store it in a cool dry place till you get to it.
My next piece of advise is...."Don't worry about it!!"

You are a beginner. Don't get attached to your first pieces.....it's just practice. You will learn faster by doing a lot of pieces rather than obsessing over your first ones.
BTW, Welcome!
Remember, this advice is worth exactly what you paid for it!!!!
Joe,
Make Chips!