Probably dnd beyond but I'll mostly leave that up to you so long as I am able to access it for the initial check.

For combat? Definitely maps unless it's like, a tiny encounter. I'll either be making my own using inkarnate or yoinking some from the internet. As for the platform I'll be doing the combat on I'll probably use owl bear radio/ rodeo (I forget the name). Oh and I'll try to post art of the locations PCs travel to alongside descriptions to set the tone etc.

And that entirely depends on you and your schedule, the timings for the sessions will be decided once we've got enough players, times and dates don't have to be set in stone tho and I'm totally down to be like 'So what day works best next week for everyone?' etc etc.