The ideal situation would be if you could sit down with the pharmacist, and they could show you the most common scenarios you encounter, and what you do in the situation - all the while, you'd be writing stuff down during their explanation. However, retail pharmacy is too understaffed for the pharmacist to do this every time. I always encourage new techs to ALWAYS make a small notebook where they can separate things into a few basic categories: insurance information, sigs, DUR overrides, and other information that you might forget. The most annoying thing is when techs consistently forget things they have been shown numerous times because they don't make an effort to retain the information - this is where the small notebook will be your best friend because you can always refer to it. Retail pharmacy is a very tough gig to get in, so it will take a long time to really feel "comfortable" in the pharmacy. I would say, it would take about 1 year of full time work in the pharmacy to feel comfortable enough that you'd be able to do everything. Lastly, the most important thing is to NEVER MAKE ASSUMPTIONS in retail pharmacy. Always see things through to the end and be meticulous even if it seems like certain things are extremely repetitive. Keep in mind that there is a clear distinction between things that a technician can do, and things that a pharmacist can do. Hopefully your manager has already made these things clear to you - always ask if you feel uncomfortable doing something because it's much easier to correct a mistake early in the process instead of going back and fixing it later.
My store still does the slow movers by brand, and that is most of what we have in stock. However, we also have serious organization issues. The shelves are SO unkempt! 
