Most guitarplayer will start out with coversongs. For some people, this may be the only kind of guitarplaying they do.
When it comes to learing a coversong you can learn to play all the parts of the song as they are on the original recording. This may be a good measure to see how good you are as a player.
Once you can play a particular song you may want to look at playing that particular song in a different setting: If the original guitarpart is mainly strumming, you could look at picking. Will the song still stand up when you pick the chords? You may have to change the rhythm a bit. Will it make the song more mellow? Good, as this means you will now have another version of the song which you can play at occassions when energetic strumming may feel a bit out of place.
It may also be possible to play the song as an instrumental: You may play chord-and melody tones at the same time, and you may also have to alter the rhythm of the song for it to work smoothly.

Developing different versions of the same song you play will teach you a lot about what is possible with the given song, it will also develop you sense of style and playing ability. It will certainly give you feedback on what you can-and cannot do at the moment.

 

Keep experiment and enjoy the process.
Eddie