The 
Lackey is a good early quest for money and equipment, but it requires clearing a bandit camp with five low level bandits which may prove difficult to some at first. But that's at the very end of this quest.
Finding Vostatek
Talk to Zlatka and Vitek at Vostatek's house west of 
Tachov, near Vidlak Pond, to learn that he is missing.
Vitek is not very helpful because of his complicated relationship with his father. You can still talk to him again for an archery contest and archery training. It is also worth buying the 
Woodsman's Journal I skill book from him, which gives Survival XP.
Travel around Vidlak Pond to the northern tip where you will find Vostatek hiding in a tree while escaping a pack of wolves. If you want to preserve your Lent run, defeat the wolves using only your fists.
After meeting Vostatek, carry him northeast past the log, ant hill and birch tree to his hideout. Then help him find his horse by following the path southeast and checking the markers and clues.
Bandit Camp & Secret Stash
At the bandit camp you cannot talk to the bandits. You could try stealing the horse at the northern edge of the marked area, but it is facing the wrong direction and usually leads to chaos. The simplest approach is to attack the camp.
The enemies are fairly weak. Only one bandit has armor and the others surrender after a few hits.
Rush the camp and kill the first archer, then lure one or two bandits away from the camp. There are five enemies in total. The leader carries the Vidlak Bandit's Map, which starts a treasure hunt.
Inside the camp chest you will find some food and 27 Groschen. Near the horse there is also a hidden stash with a crossbow, bolts, clothes and about 100 Groschen.
Rewards
After defeating the bandits, return to Vostatek's hut. He rewards you with 80 Groschen.
This is also a good time to ask him to repair the lute from the Troubadours, though you must first bring him sheep guts.
Vostatek also becomes a skill teacher and unlocks a new task questline about poachers in the area.
Lackey Quest FAQ
Where do I start the Lackey quest?
Talk to Zlatka and Vitek at Vostatek's house west of Tachov, near Vidlak Pond. They will tell you that Vostatek is missing.
Where is Vostatek hiding during the Lackey quest?
Travel around Vidlak Pond to the northern tip. You will find Vostatek hiding in a tree while escaping a pack of wolves.
How many bandits are at the Lackey bandit camp?
There are five bandits at the camp. Only one has armor. Rush the archer first, then lure one or two away. The others surrender after a few hits.
Where is the secret stash in the Lackey quest?
Near the horse at the northern edge of the bandit camp there is a hidden stash with a crossbow, bolts, clothes and about 100 Groschen.
Can I do the Lackey quest during a Lent run?
Yes. When you find Vostatek in the tree, defeat the wolves using only your fists. Wolves defeated by fists retreat instead of dying, preserving your Lent progress.