Attack Levels 1-8:
Ok now that you are off that island its time to head north. Go across the bridge you are next to and follow the gray road north. Eventually you will come to a split in the road. For now take the right path to avoid being killed by level 7 wizards. Follow this path on the right north for a short distance, and u will find your self just East Varrok. Enter the city and stop at the bank that will be on the south side of the road (you will see $ on your map). Deposit all your items except for your shield and sword, then go to the building directly across the street. Be sure to equip your sword and shield, and attack the dummy by clicking on it (note: this will only train your attack skill u can not train strength or defense on these dummies). Attack the dummy until it says in your chat box that you can not learn anymore (this should happen at level 8 attack).
Strength Levels 1-20:
Now travel east past the fountain and past the other bank at the west side of Varrok until you cross a wooden bridge. North of the bridge there are 2 fishing spots. Go north until you see a bank (note:there is no path). At the bank take out your bread and shrimp so u have some food. Switch to your desired combat mode in the crossed swords menu (I recommend strength). Go in side the building directly to the north of the bank(the one filled with level 3 men). Open the doors, walk in and be sure to close the doors behind you, this will keep men from escaping. Stay here and continue to kill men as long as you can with out dieing. Be sure that while you are there your pick up the bones of the dead men, but do not bury them (you will need these later to buy better weapons and armor). When you collect as many bones as you can bank them along with your coins, and head back south to the 2 fishing spots by the bridge. Quickly log into a popular world and ask for cooked fish. If you are in world 1 this should take about 5 minutes. Log back into a non-busy world and continue your training. At the building with the men. Only bring some of the food with you because it will last a long time, and continue to collect bones. Continue to train strength until u either get 20, or run out of food.
Attack Levels 8-20:
Bank your bones and go back into west Varrok. Go north to the Grand Exchange, and talk to the G.E. Tutor. After your talk go north and talk to a bank who is dressed in gray, and ask to access your account, and pull out the bones in note form by clicking the note button in the bottom right corner of the bank window. Once you have completed this go talk to the G.E. Clerk who is dressed in blue, and say access the exchange. Click the orange sell arrow, click on your bones, and then click confirm offer. Your bones should sell instantly, if they don't wait a little while for them to. Now that you have your money click the green buy button, and type in "scim". When you find the option mithril scimitar, click on it and hit confirm offer. Now that you have a good weapon, go back to world 1, get more food like before, and train your attack level to 20. Now you can wield mithril weapons.
Defense Levels 1-20:
After you get your attack to 20, train your defense to 20 also if you run out of food you can just go back to the fishing spot in world 1. after you have trained both skills to 20 you should have enough bones and coins to be able to buy full mithril armor. Go back to the G.E. And sell your bones, and when you buy type in "mithril a". Choose the option "Mithril armor set (l)" and confirm offer. Now that you've got your self a descent weapon and descent armor you can train on higher level NPC's.
All levels to 40:
Now with food you can attack guards. This can be done right in front of either Varrok bank. Train here with food until you get attack strength and defense to 40.
Now you will be able to wield and wear rune items. If you find that you are low on cash spend about an hour collecting bones in edgeville where the level 3 men are. Stock up on lots of food and go east of the Varrok palace in the sewers. Follow the maze of passageways until you find some level 34 deadly red spiders. My experience has proven that deadly red spiders are the fastest way for mid-level players to gain combat xp.
Now that you have combat skills above 70 you are basically master of the F2p world. The best xp at this point would be to kill lesser demons in Karamja, or cockroach soldiers in the Stronghold of Player Saftey.