Well, I hope no one minds that I post here. I have explored those websites (Humanistic and Naturalistic Paganism), because I am very attracted to Paganism but I wasn't sure if my point of view fits so I was trying to find a bridge. It was a starting point to seeing that I could have something that can be more compatible with my mind but I don't use those terms to describe myself.
Like you I don't really have reason to believe in certain things and I decided to take a more metaphorical approach to things because I still value them. I don't see a point in discarding something outright if they are still of value. I have certain "beliefs", if you will, about an overarching pantheistic deity (more akin to a force of nature like gravity) and I'm somewhat animistic (I still have to read more to see if it's an accurate term for me). But I'm not trying to force myself to be polytheistic, for instance, because I don't really view the world this way and it's pointless to force myself into it. If it happens, it happens.
To me, my main focus is this life, nature and my connection to all of it. I created some simple short rituals that are nothing fancy but nonetheless meaningful, they remind me of all I care about and am thankful for. I celebrate, in a small way, the turn of the seasons. Also, I'm currently searching for symbols of my affinities towards nature and the virtues that are important to me, to put on an altar, they should go nicely with my short rituals. It's important for me to set the mood. And I don't have any tools yet (like runes for example). I view them as psychological tools, not literally magical. But the majority of the time, it is more like small, seemingly mundane things; I absorb a walk in a park, plant a tree, gaze at the night sky, etc. I don't know if these things are intrinsically Pagan, but it started from there.
Sorry if this seemed self-focused but I wanted to share this because it took me so long to realise I could have my own approach to things. Just try it out, see if it works out for you. Don't feel like you have to force yourself to believe in things. Hopefully this is useful in at least some way. You can take my word with a grain of salt, after all I have no where near the amount of experience some others here have.
But after all this said, I'm not sure what labels to use at all. I fear calling myself a Pagan.
I'm often confused about who is and isn't Pagan (even after reading quite a few books and online resources) and I feel like I'm walking in a mine field when it comes to labels.