Here are some orders for you to farm jungle in ranking from best

1. Red Brambleback -> Raptors/Wolves -> Krugs -> Blue Sentinel
2. Red Brambleback -> Krugs -> Raptors -> Wolves -> Blue Sentinel
3. Wolves -> Red Brambleback -> Raptors -> Krugs -> Blue Sentinel
Blue Buff is least essential as it restores Mana/Energy, which you don't have.

Bot lane: You can go into the bush near right side, then tunnel for a surprise,or go from the left side wall. You can even invade if you're sure that the jungler isn't farming gromp / krugs.

Mid: If they are attacking tower, Tunnel from the Raptors if you are on right side. You can go from brush in the river or go closer to enemy turret.

Top: Same as bot lane.

You have to keep your level around the same as your teammates. Even if you are level 4, don't go ganking a level 6 even if they are at half health. Farm is important. If the gank isn't essential, don't do it.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
When you have around 1000 gold, go back and recall! Nothing is worse than countering an enemy jungler you know you can win, but getting outplayed because they have more items will only give them more gold to buy even more.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
WARDING! Warding is super important! You ward around the edge of your jungle and Red Buff. If it is early game/ you have a squishy enemy jungler, wait until they have finished stealing and then kill. You will get the buff back and even if it is just raptors or gromp the xp and gold will be worth more from the kill than the farm. If you're feeling cheeky, you can hide in a nearby bush / behind (if you have vision) then smite to steal and tunnel if you are behind a wall to kill.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Here are some tips to invade:

Ward, obviously, from the place around you nearest to the enemy base or where you think they will come from.
Use your tunnel to escape fast if they catch you and a dash if necessary.
Make sure you are high health before starting, it will only make you more vulnerable if you are low.
Use your burrow and tremor sense to see if there are any enemies. You should travel like this to warn you of coming dangers, even if they cannot see you.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
HOW TO STEAL YOUR DRAGON:

If you see the enemy team taking a dragon, you should wait. Wait until it is low health, then tunnel in. Dash out incase you got pulled away.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Anyway, that's all! This is my first guide btw.