@Lazar-Demin thanks for your swift answer. Unfortunately the update command does not work:
Downloading https://repo.onion.io/omega2/packages/core/Packages.gz
*** Failed to download the package list from https://repo.onion.io/omega2/packages/core/Packages.gz
both http and https don't work
EDIT :
Nevermind, I've found the root of my problem, the omega2 does not seem to like network SSIDs that contain special characters. I changed my network's SSID and now all is fine. Thanks for your help