what can i do to contribute to freedom and privacy on the internet
5If you have internet bandwidth to spare, do contribute.
Run an I2P node. You can install software like i2pd to run on the background and not have to interact with it in any way.
On Debian based GNU+Linux distributions "sudo apt install i2pd" is the easiest way. Altough it may not be generally recommended as the best way to do it for I2P users, for someone who just wants to contribute some bandwidth and not have to think about it any further, that's the simplest and doesn't get in the way. Just install once and no need to think about it again, Except you may also need to enable UPnP on your router if it isn't enabled already. And depending on whether there are some firewall things that block the traffic you may need to set some rules to allow the i2p ports to be used.
Its is useful to be aware of any restrictions palced on you by your ISP and you may need to deal with those if you want to contribute better.