Not having a ton of skill and experience does not mean you do not have inherent value, so act like you do. Make clear that you have gumption, an interest in learning, and a willingness to work hard.
Make the best damn coffee
Regardless of where you are in the pecking order, take responsibility for the tasks assigned to you and do them like a rock star. If you are getting someone coffee, get their order exactly right.
Do not let your job be a bad boyfriend
Women, unlike men, do not always know when their value is rising and when it is time to push for more at work. Being overly helpful and eager, waiting for your boss to promote you, is like waiting for a bad boyfriend to propose. In both cases, if you allow people to step on you, they will.
Work it in romance
Make your voice heard in love too. If something in your relationship is subpar and you do not respect yourself enough to speak up, your partner will assume you do not expect better.
Upgrade how people see you with a few simple physical cues. Do not hunch, speak clearly, look people directly in the eyes, and get your hair out of your face. Practice by doing dry runs of scary conversations in the mirror.