I'd say become friends with her first. Whenever the pharmacy isn't busy chat to her, ask her about her hobbies. Everyone loves talking about themselves so keep the focus on her. Best to come friends first and then you might work out if she's in a relationship before you ask her out for a drink. Otherwise ask her and if you're already friends she won't see it as weird and is less likely to say no. You're planning on asking her out when you've seen each other twice. You don't even know yet if you'd get along yet