If you're stood in a changing room holding a leopard print dress and asking whether it's too much, it isn't. That's the whole appeal of the print, it reads as a neutral once you've actually got it on, not the fabric. I've talked at least three people out of putting one back on the rail because they panicked at the mirror under strip lighting, which flatters nothing and nobody, leopard print included.
The easiest versions to live with are the ones where the spots are small and close together, in browns and ochres rather than stark black and white, because that's what reads as a texture from a distance rather than a print shouting at you. A washed out, pale background with faded markings is softer again, almost like a worn rug, and it's the one I'd point a nervous first timer towards. Hold the fabric up to the window if you can, the better ones have the pattern printed with some blending between the spots rather than hard edges stamped on flat, and that's usually the difference between a dress that looks expensive and one that looks like a costume. For a first leopard dress, go for a simple shape, a midi in a jersey or soft crepe that skims rather than clings, nothing with a huge statement sleeve or a cut out doing a second job, because the print is already doing plenty of talking on its own.
In an ordinary wardrobe it sits next to things you'd never think to pair with an animal print and that's where it earns a place. Plain black boots, a tan belt, a denim jacket thrown over the top on a day that can't decide what season it is, all of it calms the print down rather than fighting it. Gold jewellery works better than silver, I think, warmer against the browns, though I've been wrong about jewellery before and will be again. Avoid putting it with anything else patterned unless you genuinely know what you're doing, stripes and leopard together is a look exactly three people on earth can pull off and I'm not one of them.
It's a dress for the in between months more than high summer, worn with bare legs and sandals in September heat or with tights and boots when it turns, and it covers dinners, weddings you're not sure how dressy to be at, and the sort of ordinary Tuesday where you want to feel like you've made an effort without actually making one. If you're picking your first, go for the softer brown and cream version over the harsh black and white. It'll forgive more and you'll wear it more.