Anyone can start a Tetra. You don’t need to get anyone else’s permission or endorsement. You don’t need to have any special community organizing skills (yet). All you have to do is declare that you’re starting a Tetra for your city or town or neighborhood or friend group and then start doing stuff under that banner. Hosting a weekly event is a good way to get the ball rolling, but you can do whatever makes sense for your Tetra.
You can use the name “Tetra [your city/town/neighborhood/friend group]” or choose a different name if you want. You can generate a logo using the Sierpinski logo generator or make a custom logo yourself or just skip the logo.
To get your Tetra listed on this website with a dedicated page, send an email to dan.allison@protonmail.com or open a pull request on the tetracity.net GitHub repo. This step is not required but is highly encouraged because it helps people find your Tetra and it avoids the confusion of having multiple Tetras in the same city using the same name.
If you want to level up your community organizing skills, check out Microsolidarity and Fractal’s Campus Accelerator Program for knowledge and guidance.