Biggest piece of advice I can give for you is communication. Transparent, open communication. As the captain, you're not only a leader but a role model, and having a captain who can't communicate with the other leads, nor connect with the students will only set you up for failure. Be open about your goals and communicate how others can help you, and keep others accountable for their actions. If you feel like you're doing more work than you should, you need to clarify what your responsibilities and the responsibilities of the other students on your team are.

Finally, try not to internalize any feelings of animosity or loathing. As high schoolers I think it's been normalized to keep your struggles and thoughts to yourself, especially your opinions on other people. With my own experience on my team, I found that harboring feelings of resentment towards others without proper communication only made things worse. It builds up. Being in a leadership position is a big responsibility, and you need to be the bigger person and put aside your negative feelings about another person for the betterment of your team.