You're probably fine, but ideally the fresher the better. As long as the can isn't bulging it won't be "spoiled" so there's no danger of food borne illness or anything like that. The most likely problem is it could be showing signs of oxidation which could result in a darker color than intended and a flavor "twang" (sadly this was pretty common in extract homebrew back in the day when a lot of the extract wasn't super fresh). That said, you're not too far past the BBD, so you might not notice any issues at all. If it were me, I'd probably exchange it for fresher extract. Assuming it was purchased after the BBD, if your starter kit came from a local shop, they'll probably happily exchange it. Same if it came from an online shop; they'll probably send you a new can free of charge. It's kind of like with cooking, if you're going to take the time to make a nice meal, why not use the freshest ingredients possible?