When you first start out for best metal, what you can wield is bronze. With you levels going up, you will be allowed to wield more metals. Attack, Defense, and Strength are necessary to be trained if you want to make some good weapons for yourself. It doesn’t mean weapons only contain swords. A Battle staff or even a bow can be considered as a weapon. Even bare fists can be used as a weapon, too.
If you want to get some special weapons, it is suggested you join RS members. You can buy from online stores which sell rs accounts with items and gold together. Once you become members, you can get weapons with special attacks, powers or jobs.
For instance:
Excalibur: it can raise your defense temporarily by 10%.
Darklight: it can reduce an opponent's attack, strength, and defense.
Crystal Bow: its 80% faster than a magic bow and it does not use ammo.
Rune Claws: it temporarily increases strength and attack for that hit, but makes the attack slower.
Abbysal Whip: it transfers 10% of your opponent's energy to you.
Magic Longbow: it can do an accurate shot that will definitely inflict damage.
Bone Dagger: it Lowers opponents defense by the amount of damage you inflict. And it has a very good chance of hitting an unsuspecting opponent.
Dorgeshuun Crossbow: It does the same as the Bone Dagger.
Seercullbow: it Inflicts damage and reduces the magic level by the number of damage inflicted.
Dragon Long Sword: it can do a very strong hit at any time.
Dragon Daggers - They can do a double hit at any time.
Magic Shortbow: it can fire two quick arrow shots, but will hit with less accuracy.
Granite Maul: it can instantly attack an enemy even if you just attacked them.
Rune Throwing Axes: can hit many enemies in a multi-combat zone.
Except for these special weapons, you can buy some weapons which are only available for members to buy so it is really worth to by account from runescape accounts sell store.
If you want to buy weapons, you should take your character into consideration. If you are mages, you can buy some spells like Lunar and ancient. If you are free players, you can use Rune Scimitar which is a two-hand sword and very popular among free players. If you want to find some powerful weapons, you can use 2h sword.
There are different opinions about how to choose RS weapons. But one thing you should keep in mind is that you should train your skills high and earn some gold.