What kind of fishing rod can I get that is all-purpose?

That one "all-purpose" rod does not exist.

Since you'll be shore fishing, youll need casting distance. 7' should do nicely, and anything medium-heavy in action. Make is anyones preference, quantum, g loomis, fenwick are durable and sensitive rods.

One rod doesn't exist that will cover all that. But with two or three you could probably manage. (If you get one that's "sort-of okay" and in the middle, you'll find out that it's not especially great for most of the fishing you do.) A lot depends on the specifics -- like where you are, and what types of fish you're targeting. Is the lake fishing for panfish and planted trout? An ultralight 4 pound test spinning outfit would do. For bass, a 10-17 pound baitcaster would be more appropriate. Pier or surf fishing, anywhere from 10 to 25 pound line (depending on where you are and what you're fishing for), could be spinning or conventional. And offshore from a boat, anywhere from 12 to 40+ pound test, probably conventional. You could come up with two or three outfits to cover most of these situations, but that would likely be less than perfect for the other situations. You might want to start with a reasonable outfit for the fishing you're going to start with, save your money, and down the road buy more as you learn more about the fishing you're doing.

Any general purpose rod will be a compromise - as in 'jack of all trades, master of none'. But if I was limited to one outfit I would go for a heavy duty spinning rod of around 10ft long and a spinning reel. Not ideal, but it would catch fish in most situations. But with a budget of $300 per rod you've got enough to buy spinning rod combo and a stand-up type saltwater boat rod with a conventional reel. For an article that might help you to decide, have a look at http://www.go-saltwater-fishing.com/saltwater-fishing-rods.html. Hope this helps. Tight lines!

Ya that type of rod doesn't exist one because fish can tell if you take a salt water rod fresh water fishing, and two the types of fish you would be going after are completely different in size. If you want you can standardize to carbon fiber shafts, but you will need 2 rods most likely