Description: This is an easy one. Have fun and read carefully. Evening is coming fast. Kids are playing. Enjoy the sun setting at the horizon. Your friends are right before you. I think they can be useful. Shirts wont help. Pants wont either, but their caps can. Enjoy with your friends. Please do the needful. Papa will be happy. Eventually, i also think words are your friends. Rest is your wish!
Looking at the initial letter of every word in the description, we get this-
T his is an easy one.
H ave fun and read carefully.
E vening is coming fast.
K ids are playing.
E njoy the sun setting at the horizon.
Y our friends are right before you.
I think they can be useful.
S hirts wont help.
P ants wont either, but their caps can.
E njoy with your friends.
P lease do the needful.
P apa will be happy.
E ventually, i also think words are your friends.
R est is your wish!
So the key is pepper. But what cipher is it? It's obviously a substitution cipher since the given string still looks very much like a flag. We didn't have to try too long. We found out that it's Vigenère cipher. Decoding it with the key 'pepper', we get the flag-
pCTF{goodjobsherlock}