Are these sentences are gramatically correct..?

Not very. But the meaning is clear.

Why not address them in their native language?

btw when we say "the Festive Season" we are referring to Christmas and the New Year.

Do you know how American "Hope you guys" sounds? Why are you speaking like an American?

The speech needs to be rewritten. Would you be happy with that?

Of course..can I have your draft..?

What I meant for festive season is the gap between Summer and winter.
We have stopped play at the end of summer. Now we are going to start the new season now since summer is almost over.

Hope you guys had a good break, enjoyed the festive season, and are now ready for the new one

So welcome to all team members to a (the) new season

Hope you're all are aware about (of) our team meeting scheduled on (for) Wednesday

We can discuss new strategies and assign new Team Leaders for the season. Your suggestions/ideas are welcome

Let’s try to heal last season's wounds by improving team dedication and performance

You stopped play at the beginning of summer.
So call it the summer break or the summer holidays.
It's not the "festive season", unless you have a lot of summer festivities there.

Ok. Understood
Thank you