I wrote περπατάω but it was marked incorrect. Isn't περπατάω an accepted alternate spelling for περπατώ? Just like αγαπώ and αγαπάω.
Μου αρέσει να περπατώ or περπατάω is more usual. But not wrong of course.
I suppose you refer to this sentence ""Θέλω να περπατήσω." "https://forum.duolingo.com/comment/22425852).
περπατώ is a continuous form used in the present tense and the future continuous and continuous present subjunctive:
περπατώ (I walk/ I am walking)
θα περπατώ (I will be walking)
θέλω να περπατώ (I want to be walking)
περπατήσω is the non-continuous form used in the simple future tense and the non continuous subjunctive:
εγώ θα περπατήσω (I will walk)
εγώ θέλω να περπατήσω (I want to walk)
Wiktionary often has conjugation tables. Here is the one for περπατώ.