Perry, who split with John Mayer in February, made a brief appearance at Harper's Bazaar's poolside party Friday, wearing a white mesh top and Daisy Dukes over a pink bikini and toting a black Chanel backpack.
Sipping water and hanging out with a group of pals who included celebrity stylist Johnny Wujek and DJ Mia Moretti "she seemed really relaxed and was having a great time," a source tells PEOPLE.
While she posed for a photo with a PEOPLE reporter, Perry refused to take a solo shot, calling selfies "a disease." In fact, she hates them so much that she later took to Twitter with the warning: "Dear festival friends remember selfing is a disease."
Also at the pool party was Julianne Hough, who hosted the magazine's luncheon at The Parker Palm Springs. Sporting a flower headband that she borrowed from her 15-year-old niece, the former Dancing with the Stars pro hung out with Jesse Metcalfe and fiancée Cara Santana and was overheard talking to friends about new boyfriend, hockey player Brooks Laich.
Jennie Garth was excited about attending Coachella for the first time. Wearing a flowy black dress and gladiator sandals at The Music Lounge at Ingelside Inn, she told an onlooker that her number one must-have item for the weekend was "Sunscreen! And, of course, as little clothing as possible – you're in the desert and it is hot out here!"
Selena Gomez clearly got the minimal clothing memo – she wore see-through white lace when she hit up the fest with Kylie Jenner, later switching to an all-black outfit of crop top, skirt and sandals at the Lexus-sponsored Details at Midnight party on Friday evening, where she shared the VIP area by the pool with Dallas star Josh Henderson.
Fergie made a quick stop at the Samsung Galaxy Owner's lounge, where she snacked on pizza and chatted about her son, Axl, 8 months. The Black Eyed Peas singer was overheard talking about how she loves being a mom and how hard it was to leave her baby at home for the day. The electronics brand also hosted the Desert Voyage party, an additional bash, where Shenae Grimes kissed and held hands with hubby Josh Beech.
Former Twilight costars Ashley Greene and Kellan Lutz hung out at the launch of his Spring 2014 Abbot + Main Collection, where guests noshed on a gourmet lunch provided by Cousins Maine Lobster. Even though Greene – who rocked Koolaburra boots throughout the weekend – was there with boyfriend Paul Khoury, it wasn't awkward when she ran into her ex Joe Jonas, and they even hung out together with Jonas's girlfriend Blanda Eggenschwiler.
Aaron Paul and his wife, Lauren Parsekian Paul, were cute together as he taught her how to play Frisbee. "He was teaching her how to play and calling her 'Angel,' " says a source. "They are really in love and enjoy being together but they also socialized with everyone."
Chris Weeks / Getty
The Glee star "doted on her friends in her cabana, asking a couple of her male friends, 'Are you having fun?' " an onlooker tells PEOPLE. "She was also introduced to friends of friends and was very receptive and friendly."
Among other stars who stopped by the outdoor event were Kesha, Steven Tyler and recently engaged Emma Roberts and Evan Peters.
Perry kept up the friends fest on Saturday night, when she attended the H&M Loves Music party in a football jersey and black shorts. Once inside the event, Perry made her way to the VIP section, where Lorde was kicking back, to meet up with Robert Pattinson. Sporting a grey hoodie and a baseball hat, the actor, accompanied by his own posse of pals, and the singer "chatted and bobbed their heads along to Major Lazer before Perry eventually disappeared further into the crowd," according to a source.
Pattinson ended his evening out on the patio, indulging in Oreo cookies while discussing party plans with two of his female friends.
Jason Kempin / Getty
Meanwhile at the McDonald's & Stingray desert pool party at the Bootsy Bellows Estate, Leonardo DiCaprio and Paul engaged in some guy talk in a private cabana. And Pretty Little Liars stars Ashley Benson, Shay Mitchell and Troian Bellisario proved they're just as close off-screen – the tight-knit trio stayed together the whole night.
Also spotted enjoying some girl time, Christina Milian snapped selfies with her two pals at NYLON and Olay Fresh Effects's Neon Carnival with GUESS, while Kelly Osbourne was caught singing along to "Respect." Those that made it to the dance floor ran into Oscar winner Jared Leto, who mingled with fans and signed an autograph on someone's forearm in-between eating STK's caramel popcorn and soft pretzels and riding carnival rides.
Reporting by MELODY CHIU and PATRICK GOMEZ