I suggest to use Duolingo and other language apps as added resources in your journey. But these are tools for when you've got plenty of time on your hands and don’t have any specific language goals that you’re working towards. Have you seen the sentences that come up in some of those apps, like "La tortuga bebe leche" [The turtle drinks milk], and so on?
What Duolingo doesn’t give you is a clear roadmap to learning Spanish and customized support. With this course, you also get access to a private community and direct access to me (your teacher) where you can ask for feedback and receive extra support throughout the program.