Essays / How to start to write an essay? (help and advice needed) [7]

hi everyone,

i want to learn writing an essay, but i dont know how should i start? i read a lots and have quite lot of Vocab, Normally i can do gramatical exercises moderately well. but i can't use them on my essay. it seems to me so hard to write something . it would be so kind of you all to give me some advices.

many thanks in advance

lee