If something is "wonderful," that means it’s very good. This adjective is used a little too much, in my opinion, but because "wonderful" is so common in English, you need to know how it’s used and why. Here are some examples:
Isn’t this wonderful? (This is very good!)
It’s wonderful to see you again! (I’m happy to see you.)
I have some wonderful news I want to share with you.
Theresa says she feels wonderful after recovering from a broken leg.
This cake has a wonderful flavor.
Minnesota is a wonderful place for a summer vacation.
The people who painted our house did a wonderful job.
That was a wonderful movie. We should go see it a second time.
You are a wonderful person!
The word "wonderfully" is an adverb.
She played her part on the team wonderfully.
The play we saw last night was wonderfully performed.