The 40-year-old played his final game for Roma in May after 24 years with the capital-city side, and decided to call it a day despite being linked with possible moves to Asia and the United States.
"The first part of my life as a football player is over and now another more important one is about to begin," Totti wrote on his Facebook page.
READ MORE: Totti's career in numbers
"Until May 28th I only thought about playing football, having fun and making a significant contribution to the team.
"Now I move on, I'm turning over a new leaf."
Totti played 786 matches for Roma in total after joining as a schoolboy in 1989, scoring a club-record 307 goals, and won the 2006 World Cup with Italy.
The former attacking midfielder will work alongside new Roma sporting director Monchi, who reportedly refused to give him a new playing contract, and recently-appointed coach Eusebio di Francesco.
"I had 25 years and more of history with Roma," Totti added. "The field of play has given me so much and I tried to give so much to these people, who day after day have shown me so much love.
"The beginning of a new phase, a new adventure now starts... I want to be everything and nothing, I want to be an important figure for Rome and for Roma and truly understand what I'll do."
Japanese side Tokyo Verdy came close to signing Totti, but local media reported on Monday that the deal had fallen through after his wife turned her nose up at a move to the Far East.
Earlier in the close-season Totti, who made 58 international appearances, had been linked to a move to second-tier American outfit Miami, who are coached by his former Italy team-mate Alessandro Nesta.
But the lure of staying at the Stadio Olimpico proved too strong, as Roma continue to look for a first Serie A title since Totti helped them to the Scudetto in 2001.
"We start from square one. I need time to figure out, step by step, in a calm and sensible way, what role suits me better," he added.
"For that reason, I'm putting myself at the disposal of the club at all 360 degrees, from the youth players to the President (James Pallotta)."
Totti scored his 250th and final Serie A goal for Roma last September. He also has two Coppa Italia winner's medals, and claimed the Serie A player of the year award twice, along with the golden boot in 2007.
The retirement of their highest appearance-maker marks the end of an era for Roma.
Now they will turn their attentions to mounting a serious title challenge, having finished second behind Juventus three times in the last four Serie A seasons.