You are responsible for ensuring that you have the necessary visas - if required - for Switzerland. Given that Geneva is largely surrounded by France, it may be wise to check the requirements also for France.
A Schengen visa covers both countries (and others besides).
See https://www.schengenvisainfo.com/who-needs-schengen-visa/ for details.
Letters of Invitation
Should you require a letter of invitation, please indicate this in your registration. Details will be posted when registration opens in March 2020.