If your new, go to ::Rcrabs and kill them. It won't take long for you to get tooth half of a key and loop half of a key. Use them together to get a Crystal Key, and use that on the chest around 22 steps North West of the bank to get 5M.
If you don't want to train, there is kind of a better way. Go to ::rogueden (bring food if you have low hitpoints) and thief off of man till you have reached level 38 in thief. I don't recommend thieving off of the guard, who requires 40 thief, because he is pointless. Then thief off of the master farmer until you have reached level 55. Then, thief off of the knight of ardougne til you reached 70-75. (So you don't get caught thieving in his pockets as frequent) Next, you will go to the Hero at level 80. Do that until 99.
If you have a high ranged level, defence level, good melee weapons and/or armor, and atleast 44 prayer, go to ::corp, ::nex, ::armadyl, ::bandos, ::saradomin, or ::zamorak. At corp, pray protect from magic. At nex, pray from ranged. Armadyl and bandos, pray from ranged, but beware because you have to eat frequently, so don't go afk like you can at nex and corp. Zamorak, pray melee. Corp drops sigils, and dragon hatchet. Nex drops rings like warrior and berserker, and nex armor like torva, pernix etc. Armadyl drops shards, armadyl armor, and of course armardly hilt. Bandos drops bandos armor, shards, and bandos hilt. Saradomin drops shards, saradomin sword, and saradomin hilt. Zamorak drops zamorak hilt and shards. Best of luck with drops!
Thief requirements, xp, and main loot:
Man 400 xp: 1 - 5,000(5k) gold pieces
Master Farmer 4300 xp: 38 - Thread,
Guard 4650 xp: 40 - 25000 gold pieces
Knight of Ardougne 8430 xp: 55 - Obsidian Cape
Monkey Knife Fighter 15000: 70 Rune weapons, Black knife(and poisoned), Korasi, and Dragon Scimitars.
Hero 27500 xp: 80 - Most rune weapons and spiney helm