Well people will certainly not find it weird if you happen to go to bars alone. A lot of people go to bars alone with the intention of meeting new people. And honestly, you can meet new people easily when you are out all alone.
Moreover, other people in the bar are probably too busy with themselves to care about the fact whether you are alone or with someone. Go alone, enjoy yourself, or get acquainted with someone at the bar. Do whatever it takes for you to feel good without caring about what the people will think about it.