Don't make your attendees ask which accommodations you're able to provide. Be upfront about what you're able to do! This will encourage people who need those accommodations to apply since they will be confident that they can participate in your event. Being specific with your list of accommodations will show potential attendees that you're working to create a space where access and inclusivity are priorities. You can add questions in your FAQ section to address any potential concerns. See this event for some suggestions.
Ask for suggestions from your coaches and attendees on other things you might want to provide. For example, you may be able to provide some webcams, microphones or wifi dongles for attendees who do not have access to this at home, or costs towards childcare so attendees with children at home can focus on learning (costs covered by sponsorship).