So,It is getting close to the end of year.

Starting a sentence with a conjunction "so" is generally discouraged. It would be okay if you're responding to a conversation, but in this case you're not.

Everyone will be busy with “big house cleaning”cleaning their houses.

You don't really need to put up quotes here. I tried to rephrase it to make the sentence flow naturally, as well as to connect with the next sentences.

However, God did give me athe best lesson to start the job without excuse.

I accidentally spilled coffee on the table and the cup fell down on the floor and smashed into pieces.

Change the tenses of the verb to past tense, by adding -ed to the base form of the verb. It should be in past tense since it already happened.

So, this is the best way to start “big house cleaning” and I get to buy a new cup too.

The word "so" is used appropriately here. The word "big" doesn't really serve a purpose a here, unless it's to indicate that your house is big. The term "house cleaning" can suffice.