Mourinho replaced Mauricio Pochettino as Spurs boss on Wednesday after the Argentine's five-and-a-year spell ended in the sack with Tottenham 14th in the Premier League.
The Portuguese has won 25 trophies in a storied managerial career at Porto, Chelsea, Inter Milan, Real Madrid and United.
However, his time in charge at Old Trafford ended in the sack 11 months ago having failed to win the league at a club for the first time since he left Portuguese minnows Leiria to join Porto in 2002.
"I am humble enough to try to analyse my career. Not just the last year, my career, the evolution, the problems, the solutions," said Mourinho in his first press conference as Tottenham boss on Thursday.
"I was humble enough to do that. The principle of the analysis was not to blame anyone else."
Pochettino was let go less than six months after reaching the club's first ever Champions League final, but results domestically have been on the slide for nearly a year.
The Argentine had been keen for a bigger turnover of his squad in recent seasons to prevent his time in charge from growing stale.
However, Mourinho insisted he will not demand millions to spend in the transfer market.
"The potential of the club is huge, the potential of the players is great," added Mourinho.
"I don't need players, I am so happy with the players I have, I just need time to understand them better, to know everything about them.
"My gift is this squad, the squad is very, very good.
"One of the reasons I decided to come was them. I tried to buy some of them for different clubs, I couldn't. Some of them I didn't even try because you know how impossible it is."
A return of just three wins from their opening 12 Premier League games leaves Tottenham already playing catch up to qualify for the Champions League next season, 11 points adrift of the top four, and already 20 behind league leaders Liverpool.
Under Pochettino, Tottenham made huge progress to become Champions League regulars and compete at the upper echelons of the league, but failed to win a trophy.
Mourinho, though, believes they are capable of challenging for the Premier League title next season.
"We cannot win the Premier League this season. I'm not saying we will do, but we can win it next season," he added.
"If we win titles it will be not the consequence of me, but of the club's work, this is a package."