Some draw the parallel between Jesus cursing the fig tree with the coming destruction of the Temple. The whole Judaic system was being done away with; the law/animal sacrificial system was not producing fruit for the kingdom. The new wine skin was being prepared in Him, the true Bread of Life. Saying He was practicing WoF for us to copy seems a stretch. He resurrected Himself from death, after all.
But the fact remains that the tree was a real tree and when Jesus cursed that tree, or spoke negatively to it, His words caused that tree to die, literally.
And He explained to Peter how He did it. And He wasn't saying that it was only reserved for Him, because He's God's Son?
No. He said, "whosoever". That means Peter could do the same thing He did.
Why do you think He taught him that?
It was to let him know that he could do the same as He did.
Joh 14:12 Verily, verily, I say unto you, He that believeth on me, the works that I do shall he do also; and greater works than these shall he do; because I go unto my Father.
Mat 21:21 Jesus answered and said unto them, Verily I say unto you, If ye have faith, and doubt not, ye shall not only do this which is done to the fig tree, but also if ye shall say unto this mountain, Be thou removed, and be thou cast into the sea; it shall be done.
Jesus did not resurrect Himself.
The Holy Spirit did that.
Rom 10:9 That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.
Rom 8:11 But if the Spirit of him that raised up Jesus from the dead dwell in you, he that raised up Christ from the dead shall also quicken your mortal bodies by his Spirit that dwelleth in you.