The Angels had a decent lead-off hitter in Yunel Escobar during 2016 and the first part of 2017, but he was not a prototypical lead-off hitter who could get on base and steal bases and cause general havoc on the base paths. Cameron Maybin was this type of player and for the close to two weeks he was inserted in the lead off spot while Escobar and Trout were both injured he provided a major spark.
This is something the Angels have been truly missing for awhile now and it is something that both World Series teams have in Chris Taylor(.354 OBP) for the Dodgers and George Springer (.364 OBP) for the Astros. The Yankees have Brett Gardner (.350 OBP) and this is one of the things the Cubs were lacking after Dexter Fowler (.393 OBP in 2016) left via-free agency to the Cardinals after winning the World Series in 2016.
The Angels could go out and try to acquire someone who fits the bill or use one of their in-house options such as Ramon Flores who had .409 OBP and stole 13 bases for the Salt Lake City Bees. They could also consider putting Kole Calhoun there or acquiring a player who fits the bill.