If they are actually liberty caps, then yes, they contain psilocybin. They're one of the more popular varieties of "magic" mushroom, and they're certainly the kind that immediately pop into my head when someone says "shrooms" without specifying a variety.
I'm not sure what you mean by "picked up," but since you're asking if they're even the right type of mushroom, I figure there's at least a chance that this warning is appropriate: if you are not an expert mycologist, or at least an experienced hobbyist, it is very dangerous and irresponsible to eat 'shrooms you picked in the wild without having someone who knows what they're doing positively identify them for you. At the absolute minimum, you should research what kinds of poisonous mushrooms grow in your area and make sure that what you picked are definitely not any of those varieties. There are numerous mushroom varieties that look very similar to the "good ones" that could make you very sick or even kill you. If you aren't absolutely sure what you're taking, then even if they are the right kind, you probably won't have the best mindset for a trip when every passing hint of nausea makes you wonder if you've just poisoned yourself.
Also, 10g of wet mushrooms is probably about 1g dry, assuming they hadn't begun to dry significantly by the time you weighed them - that's not much of a dose. If it's 10g dried shrooms that you picked up from a trusted source who said they were liberty caps, that's another story - you've got about 3-4 typical doses there.