Um.. lol i made this account just now to answer your question.. So, if you look around Flowerbud Town, near the seed shop, or anywhere in the town, you'll see dome-shaped trees also known as the Mora Trees. You can get the note two ways actually.. One way is to bring your pig's heart level up to about 3 hearts and bring him to the Mora Trees to sniff out the truffles. This may take a while, though, because the pig is lazy and will sometimes lay down anywhere and go to sleep. If he starts sniffing near a tree non-stop, take your hoe and dig near the root of the tree and you'll obtain it. The other way is not using the pig at all and go crazy by yourself with the hoe digging at random roots of Mora Trees. The positive side of this method is you'll get experience with your hoe, but the negative side is your person could become exhausted and/or die. Hope I helped you out here