The Croatia centre-back switched from Southampton for £20million on a long-term deal, one of three players to trade St Mary's for Liverpool this summer, following England duo Rickie Lambert and Adam Lallana in making the switch to Merseyside.
Liverpool have also signed Germany Under-21 midfielder Emre Can from Bayer Leverkusen, Serbia winger Lazar Markovic from Benfica and Lille's Belgium striker Divock Origi, but star striker Luis Suarez has departed for Barcelona.
Despite the loss of Suarez, Lovren believes the Reds can challenge both domestically and in the UEFA Champions League this campaign.
He told Sportske Novosti: "Luis Suarez is gone, that is true. He is great striker and it would have been great if he had stayed.
"But his departure will not mean anything for Liverpool. Each player can be replaced. Liverpool bought five quality players and I think many more will come.
"I'm 100 per cent sure that we will fight for Premier League title. But not only that. We can win in Europe too."