"When I first started working I felt that I was inexperienced."
"When I first started working I felt that I was inexperienced." "When~" 「〜時は」 "I first started working" 「初めて会社人になった」 "started working" 「会社人になった」"joined the company" も使えます。 "I felt that I was inexperienced" 「未熟だったなあ」