If you're stood there holding a charm necklace, asking me whether it's silly or not, here's what I'd say: it's only silly if every charm on it is trying to tell a different story at once. One good charm, on a chain that sits properly, is never silly. A necklace dressed like a noticeboard is.
These earn their place in the everyday months more than the party ones, oddly. A single charm sits at the collarbone under a jumper all through fetbruary without anyone seeing it, which is exactly the point, it's for you. Come spring it comes out over a plain top and does something a plain top needed doing. I wouldn't reach for one over a heavy polo neck, the chain just gets swallowed and you're left with a lump under wool, but anything with a bit of a neckline, a shirt open two buttons, a simple dress, gives it somewhere to actually sit and be looked at.
If you've got none, start with one charm, not a cluster, on a chain fine enough that it moves when you do. The three for a fiver versions go green at the clasp within a month, I've had it happen, and the charm itself goes dull and plasticky looking within weeks, no matter how shiny it was on the card. A proper one in a decent plate costs more but keeps its colour and its weight, and weight matters here, a charm with no heft to it just flips over and shows you the back all day, which nobody needs. Once you've one you trust, it goes with almost anything plain, a round neck top, a simple dress, even a plain shirt with the collar open, because the charm's doing the interesting bit and the rest of you can stay quiet. Where it comes unstuck is other jewellery with its own opinions, big statement earrings, a stack of noisy bangles, a second necklace with its own chunky pendant, all fighting for the same three square inches of you. Let the charm be the one thing that's talking and everything else listening.
Keep it away from perfume and lotion directly on the metal, and wipe it over with a soft cloth now and then, that's really all it asks of you.