It can mean both. It will usually be clear from the context, which one it is. You could write "Han går en tur senere" (He will go for a walk later) to make it clear you are talking about a future action.

Thanks Isabella!

To say "He will go for a walk" you could also say "Han vil gå en tur"

jeg kun begynder at lære Dansk for 2 måned (på internet ..myself :) ) og jeg altid bruger "Vil" at sige om fremtide, er det rigtig? P/s: Jeg er mange interesserede at tale Dansk, kan i hjælp mig?