I think nobody can suggest a topic on which you can start your channel.
You have to know in what all fields you have a firm interest. Then comes the expertise part which you need to groom yourself with for atleast a few months to the point where you are confident that no other influencer has ever done such content work, after which you can start one channel and proceed.
If you do not care much about the uniqueness of your account, Picknup a topic, choose a few basics that you want to share with public and try to break it down in layman terms. Sometimes content speaks to the audience, sometimes repeated content but with easier approach and presentation skills.
Good luck.