Sixteen-year-old Lappin and his friends were chased by a local gang outside the Shrewsbury House youth club in Everton, Liverpool before he was fatally stabbed in the chest.
The youth agency, which is working with the Department for Children, Schools and Families, plans to use focus groups across England to produce two documents in March, offering safety advice to young people and managers.
An NYA spokesman said: "It's about finding out what can help young people feel safe so that they can get to activities and feel confident doing them.
"Youth workers know it's hard when you let young people walk out of the door at the end of the evening, but until young people feel safe and confident we mustn't shut that door."