I would recommend you to get tier 1 runes until you get to summoner level 20, then as akaGrim stated, you can get the Tier 3 Runes.
These are general purpose (In the sense that they can fit any champion) tier 1 runes that will aid your way to level 30 and they are very cheap:
3 × Lesser Quintessence of Fortitude +14.6 Health (165IP each - 495IP for the set)
9 × Lesser Mark of Insight +0.53 Magic Penetration (30IP each - 270IP for the set)
or
9 × Lesser Mark of Desolation +0.93 Armor Penetration (30IP each - 270IP for the set)
9 × Lesser Seal of Clarity +0.036 mana regen / 5 sec. per level (+0.65 at champion level 18) (15IP each - 135IP for the set)
or
9 × Lesser Seal of Vitality +0.72 health per level (+12.96 at champion level 18) (30IP each - 270IP for the set)
or
9 × Lesser Seal of Shielding +0.05 magic resist per level (+0.9 at champion level 18) (30IP each - 270IP for the set)
or
A combination of the above mentioned
9 × Lesser Glyph of Focus -0.36% cooldowns (65IP each - 585IP for the set)
or
9 × Lesser Glyph of Shielding +0.08 magic resist per level (+1.44 at champion level 18) (15IP each - 135IP for the set)
or
A combination of the above mentioned
A total set of runes will cost you around 1620IP, It is quite a bit but it is worth getting, it makes a difference on early game.
Assuming you will play with a 50/50 win/loose ratio you can get your complete set of tier 1 runes in less than 30 matches.
There are also many recommended champs for beginners which are usually very IP cheap, I am talking about champions like:
Ashe, very easy to play Attack Damage Carry, 450IP
Ryze, easy/medium skill Mage, fun to play and very powerful! 450IP
Nunu, easy/medium skill Ability Power 'Tank' 450IP
There are many other cheap champions in the price range of 450-1350IP, don't hesitate to buy one if you are liking its playstyle, as you may have noticed Riot rotates the free champions every week and you might want to play a champion you liked from the previous free week on the actual.
For more information on runes and recommended champions check:
League of Legends Learning Center: Champions
League of Legends Learning Center: Runes
Short answer: Yes you can. Even with the "squishest" champion, let's say "Sona"
or Karthus
But it's not worth with EVERY champion.
The best jungler are:
- Clear his jungle FAST.
- Gank in every opportunity
- Do not wait level 6 or more for ganks (at level 2~4 you usually can
gank with normal junglers)
So, if you are looking for some for fun jungle, go ahead, pick
"random" and a smite and go for it (of course, runes and mastery are
the most important thing here). But if you are trying to play hi
elo, go for the default jungler.
Best Answer
****Disclaimer: The following is very rough due to the complexity of LOL. Assume an error margin of 20 percent or more.****
Survivability Estimates:
base HP roughly 350 + 100/level.
Effective HP is harder because it actually scales exponentially... Lets go with +150/level from 1-6, +200 per level from 7-11, and +250 per level from 12-18. It starts at around 600 and reaches ~5k by end game. +50% for bruisers, +100% for tanks.
This is most accurate for builds using one MR item and up to one other defensive item. Think a mage with RoA and abyssal scepter, a DPS with QSS or Banshee, or a squishier top.
Its rough, but here is where the numbers come from:
Base HP: 375-475 + 80-120 per level
Base Armor: 30+3/lvl
Base MR: 30 + one ~40 mr item
At late game, most builds have 70-120 armor and MR. This is ~40-60 percent damage reduction, so effective health is about double base health at late game. Early game, its only about 50 percent more. Most builds also have about 400 bonus health, from a rylais, a RoA, a banshees, or something like that.
Adding the base health in, we get around 2500 base health and 50 percent damage reduction, leading to around 5k effective health.
Overall, these are still very rough numbers. A single giant belt or other defensive item can increase a champions health by a huge amount in the mid-game. Likewise, armor/mpen items and runes mess everything up.
Edit: improving estimates
Timing attacks
One important factor to keep in mind for getting kills without position advantage is what I am going to call the timing attack, a la starcraft. The timing attack is attacking right when your champion hits a relative strength. Some examples:
If you have one or more of these factors on your side, you have a good chance of scoring the kill. Try to predict these and act to enhance them, for example, by going back to shop at the moment when you can barely afford IE, to ensure it gives you the biggest advantage.