Translation:The boy does not look like his father.
‘Lijken op’ is specifically about having a resemblance to something or someone, ‘to look like’; e.g.: ‘jouw hond lijkt op een kat’ = ‘your dog looks like a cat’; ‘ik lijk helemaal niet op Brad Pitt’ = ‘I look nothing like Brad Pitt’.
‘Eruitzien’ is about your appearance, not necessarily in relation to someone/something else; e.g.: ‘ze ziet moe eruit’ = ‘she looks tired’; ‘zij zien heel beter dan Brad Pitt eruit’ = ‘they look much better than Brad Pitt’.
You can start a sentence with time if you want to add emphasis to it, but then your sentence would have to be “altijd zegt iedereen dat tegen Luke”, however normally the sentence would be written as “Iedereen | zegt | dat | altijd | tegen Luke”, so subject | personal verb | object | time | adverb, also note that we use “tegen” when talking to (against) someone