incompetent - not qualified or suited for a purpose; "an incompetent secret service"; "the filming was hopeless incompetent"

inexperienced - lacking practical experience or training

unprofessional - not characteristic of or befitting a profession or one engaged in a profession; "described in unprofessional language so that high school students could understand it"; "was censured for unprofessional conduct"; "unprofessional repairs"

bad - having undesirable or negative qualities; "a bad report card"; "his sloppy appearance made a bad impression"; "a bad little boy"; "clothes in bad shape"; "a bad cut"; "bad luck"; "the news was very bad"; "the reviews were bad"; "the pay is bad"; "it was a bad light for reading"; "the movie was a bad choice"