You can have an amazing voice and a look that's perfect for all types of media consumption. But without a great song, a song which you're the first to perform and record, you'll just be a cover artist, even if you're amazingly talented.
What can be said is that, if you look at the charts, most of the top songs are written or co-written by someone other than the performer. Find a songwriter and get the help you need. Then, evaluate songs based on the following simple criteria that have been condensed from what is commonly understood about successful country music.
True to You
A common thread among successful recording artists is the ability to transmit emotions via sound. This is regardless of genre. So, a good song for you needs to have lyrics that resonate emotionally. You must feel it. Even if you haven't directly experienced what's happening in the lyrics, the emotional context needs to seem genuine to you and you must be able to recreate it as an actor would.
There is generally no place for foul language in country music. Sure, there are country artists who have ignored this convention and been successful. Still, the vast majority of country music is free from vulgarity. If you're trying to be successful, you need to steer clear of it, too.
On sex and violence: to be sure, both of those things abound in country music ( like they do in all popular art forms). However, instead of being directly described in the lyrics, most songs only allude to sex and violence. Good country songs tame those two things and make them more palatable, often in very clever ways. Do you get it without feeling like you've crossed into TMI territory?
Many country songs are written in common keys for the acoustic guitar: E major, C major, G major, etc. This is because most country music stars strum their guitars and sing, or at least they appear as if they do. And, while the actual key varies depending on your voice and what sounds the best, you should actually be concerned with how complex the progressions are.
A good country song usually contains no more than 3 or 4 chords, and the chord intervals should be common ones: Major roots, minor 2nds, minor 6ths, and Major 4ths and 5ths. Basically, these are the beginner chords that every guitarist learns: G, Am, Em, D, C, F, E, A, B. When a different key is called for, then all you need to do is add a capo up or down.
To learn more, reach out to a clean country music songwriter near you.