"Péter likes to paint buses."
Translation:Péter szeret buszokat festeni.
Well, we keep explaining it, this time I really wouldn't get into it under a 3 years old comment since the situation has changed a lot since anyway... you can look up the forum, there are dozens of available explanations. https://forum.duolingo.com/comment/23906912 Here is one, not terribly complicated.
I'm not sure what "strict word order" is supposed to mean but I tend to think it's commonly misinterpreted. If you have the parts of speech for a would-be sentence, do they determine word order? Definite no. So, so you get to decide about word order? Well, yes BUT your decision matters. It makes a difference. You may end up saying something odd or something you didn't want.
And to answer the former question - "Péter szeret festeni buszokat" either emphasizes Péter (as opposed to someone else) or szeret (as opposed to feel neutral about it or hate it)