Is it right to say "THANK GOD" as a Muslim??

The answer is "No" its not.Why?Coz its not the way how we should address him.

As a Muslim, we are already guided with the mighty book named"Quran" and by Prophet Mohammed (peace be upon him).

So whatever we do it should be in a guided way,a way that was already created to establish peace.

According to Quran and hadith we should address Allah by the only names that the Quran and the Hadith told us.if it is not in there then we must avoid saying it.

In the quran and hadith we can find 99 names of Allah.but in actual Allah has more names which He didnt reveal them..Allah has only given us the 99 names or you can say, He has selected the names specially for us by which we can address him and express our wantings and all.

There is a hadith-whoever memorize the 99 names and remember them till his death then he will be blessed with jannah.

Not only this,Allah loves those who addresses him with his names. The possibility of the acceptance of our duas gets high when we call Him with different different names but it should be the names that He has given us.For example -if you are seeking forgiveness then address him AL GAFFAR.If you are seeking knowledge then address Him- Al Alim..

Moroever Its a sin to adress him that is not revealed. Such as God-.

Its an English word and yet its not any word written in Quran or even Hadith.and the other reason is It’s a statement that doesn’specify any attributes of Allah(swt).So as a Muslim,we mustn't address the word.Here is the hadith given below-

Abu Huraira reported: The Messenger of Allah, peace and blessings be upon him, said, “Allah has ninety-nine names. Whoever preserves them will enter Paradise.”

Source: Ṣaḥīḥ al-Bukhārī 7392, Ṣaḥīḥ Muslim 2677

Again there is an introduced term used for addressing Allah(swt) which is Khuda.

Again its not apt. The reason is as same as before.Its basically a french term which is used to adress Allah.but yet its not any name that the Quran or any statement of hadith was revealed with.Ultimately Nobody can create any new name of Allah.Because He is the one and only Almighty and He has His own name.by giving new name to Allah you are disagreeing with this attribute of Him and having SHIRK with him.cause changing Allah's name,or synonymizing his name is a catagory of destroying the belief.

So please be conscious of whatever you are saying and if you have done something wrong do seek forgiveness. May Allah bless you.