Since you are a beginner, I don't recommend getting the extra blades. You won't need the high angle blades unless you're working with expensive figured woods, and the LA plane is not a good choice for that task either, it just doesn't have enough mass. The scraper blade is a PITA to use with this plane, use a card scraper instead. As for the toothed blade, I have one and it does a nice job, but make sure you have a solid workbench with good material holding capabilities before even attempting to use it.
As for sharpening, there is a lot of good advice on these forums. I recommend getting