Welcome to our evening on time!
Please get everything ready and be present at the party on time.
Welcome to take part in the party on time.
Welcome to attend on time!
Could you tell me which is more acceptable to native speakers? And could you give me other advice? Thank you !
[AmE - not a teacher]
It sounds like you are trying to politely suggest to the invited that they be punctual? If so, you might say:
Please arrive at the party on time.
Even then, out of context, it sounds odd. Parties often are unstructured, so on-time arrival isn't a requirement. You might add:
Because we are presenting awards, please be sure to arrive at the party on time.