DIY cleaning tips

Hey everyone,
I am looking for some ideas to clean paint stain. My husband has a collection of spray paint, which he keeps in his studio. Since we live in a condo from Scarborough condos, the studio is inside the condo itself.
Yesterday, our son took the paint and started painting with it on the carpets, walls, windows and on himself. Our son is very naughty, does stuff like this all the time. My Bad!!!
So, I was thinking of hiring a professional cleaning service for this time. But before contacting them, I was hoping to know if there are DIY tricks that I could implement so as to remove the stains.
Also, it would be great if you could suggest me some tips to clean the windows as my windows always streak after washing,and also the windows get dirty unusually fast.
Also, I would like to get some tips to clean the windows that are exposed to secondhand smoke.
Hope this isn’t too much for me to ask.
Thanks in advance!
Chime in your valuable tips.