You need to realize that a verb can be either
- finite (= matches the number of the subject of the sentence) or
- nonfinite (= no inflection), which are infinitive, participles and gerunds. We are dealing with the infinitive in your example.
For an independent clause (AKA "sentence") you need at least one finite verb and unless you are making a "list" ("She laughs and sings and dances.") you use only one finite verb.
Very simple sentences use only one verb, which by definition must be finite.:
If you negate the sentence, you use an auxiliary verb (-> do, finite) + not, together with the original verb in the infinitive:
This does not hurt
-> This doesn’t hurt.
Which means you have done a bit too much when inflecting both verbs and the correct phrasing is:
Celebrations don’t hurt anyone.