It is in a way for a sort-of new player, but it does get easier, there are guides out there that show you what to expect.
you need 33 quest points so do the following quests demon slayer shiled of arav vampie slayer etc all of them except for black knights fortress
You may get rune armour by going back to Oziach after killing the dragon. He will say that you succeeded and you will finish the quest. You may then buy a rune platebody (or green dragonhide body) from him. You may also buy rune armour from the other players or the Grand Exchange. For a guide on the Dragonslayer Quest: http://gameolosophy.com/games/online/runescape/how-to-do-runescape-dragon-slayer-quest/
You must complete Galanoth's quests and buy the armour in his shop.
You have to defeat the Red Dragon 8 times. The easiest way is to gather a whole bunch of strong people and beat him.
You will need to complete the "priest in Peril" quest.
You can't, but you can complete the quest jagex makes for us.
You must talk to Galanoth and do his quest and he will level up your DragonSlayer class.
To get dragonslayer you need to do all the quests in the lair (The last quest is not that easy) and you will unlock a shop which has dragonslayer (most dragonslayer skilles are for dragons only) Hope i helped☺
Wizard Mind Bombs I believe is used in the quest "DragonSlayer". Correct me if I'm wrong. It boosts your Magic level for a short period of time.
You need to complete Ithclarins little helper quest.
I have placed a link below that should take you to a quest guide for this quest.