To see who needs help tap on the Friends icon and then on the tab with an exclamation mark (!). Here you will see all your friends who are asking for help.
To help a player who is not your friend select the Find Friends tab and any player that has an exclamation mark (!) in the top right of the profile picture is a player who needs help.
To assist a player tap on the profile picture and you will visit the player's game and see the Handshake icon where the player needs help. Tap on the icon and you will see the exclamation mark (!) on the item the player needs assistance with. Now you can donate the required item to this player.
Tap the Home icon to return to your Town.
You can also assist your Chef Club members who request items in the Chef Club chat by donating directly there.