I'm buying my first own foil or épée. What actually matters?
Buy a complete, pre-wired electric weapon from a mainstream fencing brand, in the right blade size, with a grip that fits your hand, and do not overthink the rest. An electric weapon works fine for dry practice, but a dry (non-electric) weapon can never be scored on a box, so skip dry unless your club only fences dry. Size matters for kids: USA Fencing limits blade length in its youngest events, so check the blade size finder before ordering. Plan to own two working weapons eventually, because one will fail at the worst possible moment.
The parts matter more than the name printed on the blade. Pick a common point system so spare tips, screws and springs are easy to find and borrow; for foil, the German-style point is what nearly everyone uses. Match your body cord to the weapon's socket, since foil and épée plugs differ and foil has two socket styles. A clear guard pad instead of felt lets referees check the wiring at a glance. A standard guard outlasts an ultralight one, which dents more easily. Whatever you buy, add a few spare screws and springs to the order.
Blades come in two broad families. Regular non-FIE blades are cheaper and are what most beginners and club fencers use. FIE maraging steel blades are required at international events, generally last longer and cost a lot more. Within either family, stiffness varies: a softer, whippier blade bends easily and suits flick-style touches, while a stiffer blade gives more point control and holds its shape better. Many coaches steer beginners toward medium or stiff and away from the very softest blades, which pick up bends quickly. The best test is borrowing a few club mates' weapons for a bout each and noticing what you like.
A budget weapon is completely fine for your first year or two. Blades break whatever they cost, and a beginner's rough distance and flat lunges are hard on them. The smart money goes on a decent basic blade plus good point parts that are easy to repair, and when the blade snaps you keep the guard, grip and pommel, so the next one is just a blade swap. Be wary of rock-bottom, no-name electric weapons with knockoff points, because flaky electrics are the most frustrating failure in the sport. Grip choice and blade lifespan each have their own answer, linked below.