He’s Church of Christ or at least was and they are extremely anti-Catholic (I remember reading/hearing somewhere that he was asked to cut his connection to the Church of Christ due to various reasons). Some of his books may not come out and say anti-Catholic things but they are there. They are also rather light in terms of understanding Christianity (more pop pyschology and self-help written in terms of Christianity than actual teaching). He also treats serious matters very lightly.
His children’s books I can’t speak to but avoid most of his writings. They are too weak and light and not really helpful. I was reading one about the Cross and what that meant and spent the entire book correcting it because he didn’t fully understand what Jesus did (he treats Jesus as a beer drinking buddy and made subtle anti-Catholic remarks) and doesn’t fully articulate what Jesus and the Cross really mean to Christians. The Cross isn’t a get out jail free card though that’s how Lucado treats the subject.
There are other authors out there that are better. CS Lewis, Catholic authors such as Scott Hahn and Jimmy Akin, etc.