Is my line too heavy?

[gutted_]

First of all, I should say that I don't know a ton about fishing. I'm 18, and I haven't been fishing since I was 11 or 12. For some reason, I really have the urge to get back into it now, so I've been talking to my friends about it and researching different rods. After a lot of research, I decided on getting a 6'6" Ugly Stick GX2 spinning combo. I picked up the rod tonight along with some different kinds of bait and some SpiderWire Stealth Braid that's 50 lb test with 12 lb test diameter. I picked the line because 1. It was on sale and 2. The friends I'll be fishing with sometimes fish for carp, musky, flatheads, and other larger fish, so i wanted a strong line. It was only after getting home that I saw small text on the rod stating its meant for 10-15 lb test line. Should I return the line I bought because its too heavy or will it be okay? I'd greatly appreciate any advice you guys can give me
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