Well, this depends on the media.

There's a certain video game called NWN2 I used to play wherein I tend to fall to the good ol' Hammerspace trope, for instance. If you're not familiar with the trope, it's about having the ability to pull various stupid things out of nowhere. In this case? Throwing axes. Like, nigh infinite throwing axes just somehow fitting on the belt, on bandoliers, in the character's backpack... Because he could throw something like seven or eight throwing axes in one combat round people would exasperatedly ask "WHERE DID YOU GET ALL THOSE AXES?!" and he'd just smile, shrug, and yank out several more.

But most of the time I like to be far more serious. There's good videos to be found on the web about how much you can realistically carry. For medieval fantasy adventuring, I go for something like this:

[list][*][b]HANDS:[/b] This is where you can carry a large two-handed weapon, such as a polearm, greatsword, crossbow, longbow, or battleaxe. You realistically cannot sheathe these weapons, so either putting them on a cart or carrying them by hand is your only real option. If you forgo a two-handed weapon, perhaps you carry a large shield with your hands.
[*][b]HIPS (BELT):[/b] You can typically carry a sidearm or two here, such as a longsword, warhammer, or a mace. You can potentially have a quiver of arrows on one hip, or even a quiver of arrows or bolts and a shortbow. Notably, it's quite easy to have a spare dagger or a buckler here with whatever weapons you have, making the buckler a very lightweight and easy extra weapon to bring around. Pouches located on the belt can carry various supplies, and you can always have a couple throwing axes tucked onto it. Just think realistically about how much room is on that belt. A sidearm, a dagger, a couple pouches and a couple throwing axes is reasonable. Ten throwing axes and twelve pouches is not.
[*][b]BACK:[/b] You can strap certain shields here. You can also have a quiver of arrows or bolts. Javelins can go here, too. But you reasonably can only carry, like, one thing on this spot.
[*][b]BANDOLIERS:[/b] If you have a bandolier going over your chest it's not a terrible spot for things like daggers or potions or alchemical tools (smoke bombs?) or what-have-you.
[*][b]A SPECIAL NOTE ON SLINGS:[/b] Slings are a very interesting weapon in that while they're generally crappy, they can be carried really easily because they weigh just about nothing. In the real world they were more useful than early bows for a time, and ancient slingers often wore a lot of them: as armbands, as headbands, as cords around their belt, etc. So if you've got a pouch of lead bullets or stones, you've got lots of places to wear slings.
[*][b]A SPECIAL NOTE ON DAGGERS:[/b] You can fit knives just about anywhere. Boots? Check. Up your sleeves? Check. On your legs? Check. At some point it can become uncomfortable, excessive, and give your enemy free daggers to shank you with in a grapple, but hey: you can have lots of daggers. If I were being realistic, I would try not to go overboard, especially if you're wearing armor.[/list]

So here's a few examples of reasonable adventuring kits:

Wulfric is an old, grizzled mercenary that fights in the thick of the melee. He wears a gambeson with a breastplate over it, and his weapon of choice is a halberd. He likes the halberd because he can use it as a walking stick while traveling, and it's a very versatile weapon. He has a dagger in his left boot and a mace as a sidearm, and he keeps a buckler on his belt as well. His only other weapon is a hand crossbow, a weapon he chose because it's easy to carry on his belt, but he doesn't use it very much.

In contrast, his traveling companion Edgar loves crossbows. Edgar carries a rather large, high draw crossbow as his primary weapon, so he carries it everywhere, and he wears brigandine armor because it's easy to repair. Besides his crossbow, he has two daggers: one on his belt and one in his boot. He also keeps his quarrels of bolts on his belt, a small shield strapped to his back, and a falchion at his side.

The third member of this entourage wears a simple shirt of mail with a tunic and pants. His name is Arthur, and he was a shepherd before he was an adventurer, and so he knows how to use a sling very well. He prefers to travel light, so he carries nothing in his hands when traveling, but he has a buckler at his side and three slings: one used as a headband, one dangling from his belt, and another wrapped around his right wrist. He has two pouches of ammunition at his belt: one of lead bullets and one of stones he gathers while traveling. He also keeps a knife handy at all times and he's gotten pretty good with the longsword he uses in conjunction with his buckler. He carries a backpack and is in charge of keeping most of the group's camping gear. He tends to drop the pack before a fight.

The above three characters all have pretty reasonable loadouts of equipment. Like... You COULD have more, but if you're shooting for realism you can quickly depart from it. The more weapons you add, the more inconvenience you get.