Chances are, you already read signs & symbols around you either unconsciously or in a limited fashion, EVEN if when reading the title you were to think, “What the heck does that mean??”
I had been reading omens and clues for some time before my awareness caught up with that I was doing so. Still, sometimes I forget that EVERYTHING is a sign or clue from the Universe. Why do I believe everything is a sign? Well, I fall into a gray area on pretty much everything depending on whose viewpoint I am considering. A lot of factors make up our individual perspectives and therefore our realities, so it is really hard to nail down a limitless thing as limited in its possible interpretations. But I make an exception here. At least for the last few years I come to the same conclusion from my perspective every time I look at this particular statement and contemplate it: Either EVERYTHING means something, or NOTHING means anything.
Yeah, I can go round and round on this one like a hamster in a wheel FOREVER, but I always end up in the same place. Odds are there are much greater minds who have concentrated on this thought and perhaps even written books about it, but my conclusion is that everything means something.
That being said, I also believe the Universe, which wants our expansion (because our own expansion is LITERALLY the expansion of the Universe), gives us clues and signs the way we can most clearly understand them. This can be in all sorts of ways, from signs on highways to 
numbers and license plates, through songs and lyrics and sounds and noises and random people and animals and feathers and stuff we see on the sidewalk and tarot and oracle cards and probably most obviously, in dreams, just to name a few. Personally, I speak mediocre to fluent “license plate”- depending on how clued in I am, and I am pretty well versed in animal symbolism. I am strong in Tarot, and that comes second to my strongest symbolism interpretation ability, which is dreaming. A Course in Miracles points out when Adam (which literally translates to “man”) goes to sleep in Genesis, he never awakens. Because I am an avid dreamer, this helps me to approach what I may call my “waking life” in a similar way to my dream interpretation approach. Then I also tend to look at signs & symbols not only more objectively, but also as I do when I am lucid dreaming. I can ASK them what they are trying to tell me. They are no longer OUTSIDE of me, something that is a random occurrence, but something that lies within and is trying to communicate with me some nugget of information to aid me on my journey, or giving me a clue as to where I should be looking within for inward healing and peace.
My experience is that the more I am OPEN to signs and symbols and ALLOWING them to 
speak to me, the better I hear/understand what they are trying to communicate. It has taken me a lot of practice and it still takes more and more practice to encourage this way of connecting with intuition and with Source so that I relearn it as habit and discard the habit of tuning all out and only taking things at a super surface value.
Fortunately today, there are a ton of resources online, from blogs and websites, to YouTube videos, etc. as well as books, other free-thinkers all around us, and most importantly through our own inner guidance once we are willing to perceive it and learn to once again trust it and to know it completely. At least, this has been the findings on my personal journey.
A few references I use rather often (especially if my meditation game is low and my connection to Source is becoming cloudy due to fear blockages) are:
• “Angel Numbers 101”, by Doreen Virtue
• whats-your-sign.com
•sacredscribesangelnumbers.blogspot.com
• spiralseatarot.com
• ethony.com (whom you can also find videos for on YouTube)
• hibiscusmooncrystalacademy.com
I use a lot of resources for many things, and Google can lead to some of the most amazing sites, but these are the ones I use predominantly because they resonate with me for information on numbers, animals, tarot, and crystals specifically.