OpenVPN Server with Username/Password Authentication

Another question: I’ve messed up my client.conf file by previously installing a user cert & key files to my client. Even though I completely removed openvpn & reinstalled it, it did not create a new client.conf. After doing the openvpn command to setup the use of the client it still contained the following:

ca ca.crt
cert Laptop.crt
key Laptop.key

What should I do with the latter 2 lines?

Also, I do not yet have a static ip address (for my router) & ddclient has disappeared from the Ubunto repos. What’s the recommended procedure (in Precise & Trusty) to use hostname provider?