"I am tired and I want to sleep."
Translation:Ik ben moe en ik wil slapen.
Willen is a modal verb, which means that the second verb is simply infinitive without the "te."
A more thorough explanation is thus:
The confusion comes from a false sense of equivalence between Dutch and English. In English, the infinitive form of a verb always includes the preposition "to." Examples being: To run, to walk, to laugh, to cry.
So when you say "I want to eat" in English, you're NOT saying "I want to -blank-." Because you'd never say "I want to book" or "I want to taco," because that's nonsensical. Therefore, the formula we're looking for is something more like "I want -blank-." "I want flower, I want love, I want TO EAT." And that works, because "to eat" acts as one unit. Inseparable in this context.
Back to Dutch. It works the same way, except that in Dutch the infinitive form of the verb doesn't include "te." The infinitive is signified simply by an "-en" or "-n" at the end of the verb (most of the time).
So if we go back to our formula ("I want -blank-" = "Ik wil -blank-"), we can say things like:
"Ik wil appels, Ik wil sap, Ik wil SLAPEN."
Your Dutch equivalent of the English "to" is contained in the en there.
Hope this helps!