I don't know when/ at what level I should purchase runes at. I'm currently level 15 and am trying to fully ultilize masteries. I also want to purchase a few champs to expand my choices when it narrows down to me picking last in the lobby. I'm currently saving up for a better jungler 
and a better midlaner that suits me. (Current mid: 
; I want 
) Any hints, tips, or tricks that can help? :) I'd Appreciate it.
Level 20. Because that's when you unlock access to the Greater Runes.
20, whenever you can buy tier 3 runes. Anything lower is just wasting IP. I suggest the standard first two rune pages be flat armor seals, flat/scaling mr glyphs, and either attack speed marks and AD quints, or mpen marks and AP quints. These rune pages will service most every champion reasonably, AD and AP respectively.
I doubt Kha will be a better jungler than whatever you're currently playing to be honest. But uhm, generally for finding champions that fit you you want to try them on free week first. Feel free to try out 
and 
mid this week and 
jungle. However in jungle's case without runes any champion you try will probably not live up to their potential.
30, just learn mechanics before you buy runes, and save for runes. a full rune page is way better than slowly getting runes because playing without them teaches you how to play safe and pick your engages early game, whereas when you have a full page you should for the most part know everything you should be doing in laning phase
Level 20 because then you can get the highest tier runes. Start with flat armour yellows then flat magic resist blues because no matter if you're AD or AP you'll make good use of them.
Whenever it is you can buy tier 3 runes.
Tier 3 runes are unlocked at level 20. Don't bother buying T1 or T2 runes.
I'd recommend these two pages to start with.
Page 1: AP Quints, Magic Pen or AD Marks, Flat Armor Seals, Flat MR Glyphs Page 2: Attack Speed Quints, AD Marks, Flat Armor Seals, Flat MR Glyphs
21 But save up until you get there. Having a defensive set of runes with flat armor yellows and flat MR blues with AD and AP setups on reds and quints will be crucial to your level 30 experience.
Level 20. You can start to purchase tier 3 runes beginning at level 20. Whenever I make a new smurf I tend to buy the champ I intend to one trick up the ranked ladder with ip and then save all the rest of my ip afterwards for runes. When I hit 30 I have a full rune page and set up for that champ and enough leftover ip to buy the cheapest 15 champs and can proceed to one trick the champ in ranked efficiently.
So, level 20. Start filling out that rune page.
