I don't know why you have posted this here but if your instance accepts anyone creating new communities it would just be a case of logging in on a browser and then you should have a "create community" option in the "burger" menu.

Do consider though not making more communities on Lemmy.world, there are already far too many communities hosted on there. Ignoring the extremely questionable opinions and actions of the Lemmy.world admins it is counter productive towards decentralisation to keep having so many communities hosted there. We don't need another reddit.

Good luck with your communities :)