need help deciding on where to rent

brooklyn

depends on your budget- brooklyn would certainly be closer to your work. once you can get an idea of how much you can/want to spend each month, your answer will be fairly apparent. the vast majority of the 5 boroughs are safe for a single female- you will want to walk around at various times of day and night to come to your own personal conclusion on what you're comfortable with.
best of luck and welcome

you are from Africa and you are trying to figure out which part of Manhattan is safe?

What can be really challenging for folks to appreciate until they live in NYC is just how different particular blocks can be within NYC. You need to figure out the particular block AND your likely traveling blocks (e.g., routes to commute to your job/school, the grocery story, the gym/park, etc.). What is the program that you are participating in? You might want to call them for advice on this matter. Good luck and welcome to NYC - one of the things that makes our city great is the influx of many cultures, so thank you for coming and being part of that.

>routes to commute to your job/school, the grocery story, the gym/park, etc.

what?
This is the epitome of " privilege".

Don't do Inwood. Too inconvenient and won't give you any sense of being in the "City".

You might consider Jersey City or Hoboken as will likely be shorter commute and cheaper. Same for St. George, Staten Island if you can walk to ferry.

"you are from Africa and you are trying to figure out which part of Manhattan is safe?"

This is the epitome of "ignorance".

116th Street in Harlem has a large African immigrant community as does the West Bronx. The number one thing you need to determine in budget and that'll likely dictate where you end up.

I would recommend finding an apartment in a neighborhood that allows you to walk or bike to work. The public transportation system in the NYC metro area is currently a disaster.