"They're cool," the rapper, who is signed to the Fall Out Boy's Decaydance label, told PEOPLE after a performance at Crash Mansion in L.A. Friday. "They don't care about the media, they don't care about being famous, the money – they're young and having fun."
The rapper said he got to know the couple when Simpson joined him and Fall Out Boy on the Young Wild Things tour a year ago. "She'd listen to my song and be like, 'this is my favorite song!' She's real cool."
As for wishing the couple, who tied the knot on Saturday, good luck, Tyga said, "They don't need no good luck. They don't need no wishes. They've got everything they want in the world."
The newlyweds' friend Lucy Walsh also said that the couple are perfect together. "I'm happy for them! It's really like a fairytale," she told PEOPLE Sunday.
The singer, who used to play keyboards in Simpson's band and was a label mate of Wentz adds, "They're really good together because they're both creative, rambunctious and spontaneous. They just have a blast. The best is when you are kindred spirits and I really think Ashlee and Pete have found that."
Reporting by SHRUTI DHALWALA and JESSICA HERNDON