Describe the relationship that the people in the photograph have.
the close friend, a young's couple in love and an engagement ring
the close friend, the youngs's to be are in love...to be engaged
1the close friend, 2the young's to be in love...3to be engaged
1There are two, so "Two close friends" or "close friends" Maybe even "best friends keeping a secret"
2The use of 's is actually not quite so much as students studying English are taught. It is used as a contraction, or short form of is "it is=it's" or not as it "are not=aren't". You would not use it to contract "is" "not"after proper nouns, mainly after pronouns like nouns, like young is=young's. The bottom line is, if you can spell it out, you will be right. Better to write is not, than isn't. Much better to write "the young are" rather than find a contraction.
Young couple in love.
3. This photograph is a wedding photo. Best caption would be "newly married". To correct your sentence, try: "The couple is engaged.".
You are doing great!