JOHN Travolta, a recent father, says he plans to be picky when it comes to considering new movie roles. ''I started out with an Oscar nomination, and I proceeded to have enormous hits,'' Travolta said in next month's issue of Redbook magazine. ''But I never got another nomination. So I'd like to be in a film where there's the kind of role that would be artistically deserving of, you know, where I started.'' Travolta, 38, first gained fame as Barbarino in the TV show Welcome Back Kotter. He went on to become a 1970s sex icon as a disco dancer in Saturday Night Fever, which earned him a 1977 Academy Award nomination for best actor. He is married to 30-year-old actress Kelly Preston, who gave birth to their son, Jett, last autumn. He says he avoids Hollywood when possible, preferring Florida. Recent films include Look Who's Talking and Look Who's Talking Too. Travolta says he will star in Look Who's Talking III, but has turned down other work offers.