I2Pd should automatically manage your tunnels. You can view the admin panel at

If it's not available, you may have to edit the config at /etc/i2pd/i2pd.conf and put your node's IP in place of 127.0.0.1 for the admin panel host IP. Then restart I2Pd.

After I2P bootstraps for a few hours, it should be able to connect to most .i2p urls.

You can bootstrap Bitcoin core with the I2P nodes at the bottom of this file: https://github.com/bitcoin/bitcoin/blob/master/contrib/seeds/nodes_main.txt#L681

You can connect to these nodes with -addnode or -seednode in your configuration file (bitcoin.conf).

After Bitcoin core has peered with an I2P capable node, it will begin gossiping and peering with other I2P Bitcoin nodes as necessary.

Once you have connections you can view your I2P (and Tor) peers: