We gothave a lot of things to do.

"got" would work colloquially, if you want to say "We've got a lot to do."

At first, it was just a basic room, in which there arewas a double bed, a desk, a chair, and a TV which we seldom watch due toused since we like to watch yYoutTube.

So, we bought some furniture whenever we came up with "If we have something in our room, that would be good" thoughtthought we needed something.

We bought two shelf (ves: one is for storing food ingredients such aslike garlic, salt, sugar and etcetera, etc., and the other for putting our clothes ),. We also bought two rice cooker  ( s (so that we can cook rice and soup at the same time. ), a stove, a gas barrel, and a extension cord and so on.

Periods don't belong within parentheses ( ). Also, you can split the list in half to make it easier to read, since you've given explanations for why you bought the shelves and cookers.

Baecaused onf healthy issues and the fact we arethat we got used to the food here ( too salty, too sweet, and too spicy for us ), cooking byon our own iwas inevitable.

We didn't notice that we have bought a lot of furniture until now that we are leaving this place.

We sold some furniture to our colleague who'se wife just gave a birth to their first girl.

who's means who is

Due to hisSince he just had a daughter, we gave him  a very cost-efficientgood price( (a 30% discount).

You could also say that you gave them a good price. Also, I think you're trying to say that you gave him a good price since he just had a daughter, and not because he had a daughter.

We are going to move house to another place.

We gothave a lot of thing to do.

At first, it was just a basic room, in which there arewas a double bed, a desk, a chair, and a TV which we seldom watched due to we like to watching youtube.

The verb tenses need to match, in my opinion.

So we bought some furniture whenever we came up withthought "If we have something in our room, that would be good." thought.

We bought two shelfves ( one is for storing food ingredients such as garlic, salt, sugar and etcetera, etc, and the other is for putting our clothes ), two rice cookers  ( so that we can cook rice and soup at the same time. ), a stove, a gas barrel, and an extension cord and so on.

Based on healthy issues and the fact that we are used to the food here ( too salty, too sweet, and too spicy for us ), cooking byon our own is inevitable.

We didn't notice that we haved bought a lot of furniture until we are leaving this place.

We sold some furniture to our colleague who's wife just gave a birth to their first girl.