My thoughts (for what they're worth)
I would agree that going to a store a little ways from where you live is a good idea. Also, I like to go early in the day during weekdays if possible. I find there are fewer people around to make you feel nervous at that time. If there is a SA there you can start with casual conversation (since there will be not many customers you can chat about weather, current events, whether they have any sales on, whatever) and after you feel a bit more comfortable you can ask advice about stuff that may look good on you. It will be embarrassing but I recommend asking to try stuff on as well (I always ask if it is ok with them because "I don't want to make you uncomfortable"). This will give them (and you) the opportunity to bring you more items that may work well with what you are looking at. ALWAYS be polite, friendly and courteous since many customers can be very dismissive and rude. The more polite and friendly you are the more likely they will be to want to help you and see you as a decent person rather than a weirdo. I have done a lot of customer service jobs and I would rather have someone who asks for something out of the norm or looks strange but is super nice to deal with than someone who is a jerk that wants the most common or easiest thing in the world. You will feel nervous and silly and embarrassed but that is how many people feel when learning any new skill. The more you do it and build relationships with the SA's the easier it will become. Just my thoughts.