It's not an has/have distinction, actually. The form ha is the infinitive and the form har is the present tense. In English, these two are the same for the most part, but you can see the difference in third person singular.
- Jag har en boll = I have a ball
- Hon har en boll = She has a ball
- Att ha en boll = To have a ball
So, for questions like "Are you doing (XYZ)", you just switch around the subject and the verb? If there was a direct object, would it be something like "Äter du mat?" or "Talar du svenska?".
Also, how would you ask "Are you (XYZ)?" in terms of adjectives, not verbs? Would the subject and the verb (in this case, är) get switched around like before? "Du är glad" into "Är du glad?"?
In Swedish how do I distinguish the question "are you working" as in "are you performing your labor at this moment" versus "do you work" as in "do you have an occupation/job"? because those two sentences do mean different things in English. Is this something that is only distinguished contextually?