Summarize the following:
You may want to bring some food. You will need to set recovery questions. Look it up on the RuneScape website in order to do this. There is a full guide in doing this here. At this point, you should have 20k gp, some cool boots, gloves, and 2 XP lamps giving 500 XP each. Spend these lamps on defense. You may also wish to do the Swept Away Quest for additional XP. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/4\/4c\/Make-a-Defence-Pure-on-RuneScape-Step-5Bullet1.jpg\/v4-460px-Make-a-Defence-Pure-on-RuneScape-Step-5Bullet1.jpg","bigUrl":"\/images\/thumb\/4\/4c\/Make-a-Defence-Pure-on-RuneScape-Step-5Bullet1.jpg\/aid482873-v4-728px-Make-a-Defence-Pure-on-RuneScape-Step-5Bullet1.jpg","smallWidth":460,"smallHeight":345,"bigWidth":"728","bigHeight":"546","licensing":"<div class="mw-parser-output"><p>License: <a rel="nofollow" class="external text" href="https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/">Creative Commons<\/a><br>
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<\/p><\/div>"} With your newly earned money, you may want to buy some armor and accessories, or use it to make some more money. Remember, the more money you have, the easier it is to make more. 13 combat with 400, or 27 combat with 990). If you wish to do this, do not train by killing monsters. You will have to use XP lamps, and other passive means of getting XP. If you wish to train hitpoints too, you're going to have to find a weapon. Some suggestions include an Iron Dagger, Iron Scimitar, Blurite Sword, Silverlight, or a Runecrafting Talisman Staff. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/7\/78\/Make-a-Defence-Pure-on-RuneScape-Step-6Bullet1.jpg\/v4-460px-Make-a-Defence-Pure-on-RuneScape-Step-6Bullet1.jpg","bigUrl":"\/images\/thumb\/7\/78\/Make-a-Defence-Pure-on-RuneScape-Step-6Bullet1.jpg\/aid482873-v4-728px-Make-a-Defence-Pure-on-RuneScape-Step-6Bullet1.jpg","smallWidth":460,"smallHeight":345,"bigWidth":"728","bigHeight":"546","licensing":"<div class="mw-parser-output"><p>License: <a rel="nofollow" class="external text" href="https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/">Creative Commons<\/a><br>
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<\/p><\/div>"} Some suggestions for enemies to train on are monks (near Edgeville), cows (for their hides, which are worth decent money), chickens, or goblins (the last three can all be found in Lumbridge). Remember that bones are worth a fair sum of money and collecting these could be a good source of income. Do not bury these bones as it will increase your prayer, which does affect your combat level. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/5\/55\/Make-a-Defence-Pure-on-RuneScape-Step-6Bullet2.jpg\/v4-460px-Make-a-Defence-Pure-on-RuneScape-Step-6Bullet2.jpg","bigUrl":"\/images\/thumb\/5\/55\/Make-a-Defence-Pure-on-RuneScape-Step-6Bullet2.jpg\/aid482873-v4-728px-Make-a-Defence-Pure-on-RuneScape-Step-6Bullet2.jpg","smallWidth":460,"smallHeight":345,"bigWidth":"728","bigHeight":"546","licensing":"<div class="mw-parser-output"><p>License: <a rel="nofollow" class="external text" href="https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/">Creative Commons<\/a><br>
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<\/p><\/div>"} When you hit 40 defense, you can wear any type of Rune armor, except for the platebody (Dragon Slayer quest required). If you've made a lot of money, you can buy something fancy, like gold trimmed. You may even want a gold trimmed wizard robe for style, as you can't wear a gold trimmed platebody. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/f\/f4\/Make-a-Defence-Pure-on-RuneScape-Step-7Bullet1.jpg\/v4-460px-Make-a-Defence-Pure-on-RuneScape-Step-7Bullet1.jpg","bigUrl":"\/images\/thumb\/f\/f4\/Make-a-Defence-Pure-on-RuneScape-Step-7Bullet1.jpg\/aid482873-v4-728px-Make-a-Defence-Pure-on-RuneScape-Step-7Bullet1.jpg","smallWidth":460,"smallHeight":345,"bigWidth":"728","bigHeight":"546","licensing":"<div class="mw-parser-output"><p>License: <a rel="nofollow" class="external text" href="https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/">Creative Commons<\/a><br>
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<\/p><\/div>"} If you are still F2P, note that continuing your defense will be extremely slow. If you want to continue your defense, membership will make things a lot easier. However, if you wish to stay at 40, you can always train skills, and earn money, and improve your character.

Summary:
Completing both strongholds now is highly recommended. Head to barbarian village. Complete the Stronghold of Player Safety. Decide on whether or not you're going to remain at 100hp (If you're at 100hp, your combat level will be lower, i.e. Remember to upgrade your armor as you hit the defense levels 5, 10, 20, 30 and 40.