if you hover over your profile picture, in the top right, it will reveal a menu. Click 'Account' and it will bring you to your account settings. Click on 'Profile Settings' in the sidebar and scroll down until you see a 'Signature' box, that's where you can add whatever you want. Then save your settings at the bottom.
yeah. I only got into the series last year after playing a few of the old retro games on my switch. I started with links awakening for the gameboy then played a link to the past on the gamecube. The result of that was getting both breath of the wild currently 71.23% complete and tears of the kingdom which ill play next