After two years with Sauber, Perez has moved up to one of the sport's most successful teams as replacement for 2008 world champion Lewis Hamilton following the Briton's departure for a new challenge with Mercedes.
"As a Formula One driver, you dream to win your first race. It's something you have dreamed of all your life," Perez said ahead of his McLaren debut in Sunday's Melbourne season-opener.
"I have no idea what it feels like. I have to be honest, I am desperate for winning. I haven't won a race yet in my (F1) career so I am desperate to get a win," he added.
"But when I ... start the season I will just drive normally, I will not be driving desperately to get my win. I need to be consistent, I need to score points and I know the win will come at some point."
Perez has not scored a point since he was announced as McLaren's new signing, a run of six races since he was 10th in Singapore last September.
Before that he had chalked up three podiums, including two second places, for a solid mid-table Swiss team who make the most of their limited resources but rarely challenge for victories.
A Ferrari academy driver, he had been linked with the Italian team as a possible replacement for Felipe Massa before McLaren - winners of seven races last year - snapped him up in the wake of Hamilton's shock decision to leave.
Even if his last race win dates back to the GP2 support series at the end of 2010 and his new team-mate is Britain's 2009 world champion Jenson Button, McLaren do not see Perez as an apprentice.
"Sergio knows that we expect him to race hard and not come and be content to park the car two grid places behind Jenson. It's not what we hired him for," said McLaren managing director Jonathan Neale.
"I expect him to be trading places with Jenson from the get-go," he added.
"When I look up at the timing screen I want to see them close ... then we know we've got each side of the garage really competing, which is what we've set the system up for."
Button and Hamilton were both champions, and while Hamilton was usually faster he scored fewer points than his team-mate over their three years together.
Perez and Button - winner three times in the last four years in Melbourne - have already made a solid start and McLaren are pleased with how well the new arrival has adapted to his surroundings and working with new engineers.
"We have high expectations of him," said Neale. "He'd better be up the front, that's what we pay him for - if the car's capable. If we give them a package in which we can show that the car can be qualified in the top three or four places then we expect wins from both of them."
Perez would become the first Mexican to win a grand prix since the late Pedro Rodriguez in Belgium in 1970 and will feel some of the burden of expectation lift off his shoulders.
Not all of it, however. The Mexican has repeatedly stated his target is not just to win races this season but to win the championship.
"My target is to beat Jenson and to beat all the others," he said.