One of my favorite YouTube channels called Kevin’s English Room posted a video today, and in which they introduced a hamburger called bthe Baconator from Wendy’s.

I knew theabout Wendy’s firstalready, so I searched for it and I found that there isn’aren't any shops aroundin my area.

I was disappointinged….

It seems there are the shops in Osaka and Kobe, so I wanted to go there next time.

"wanted" is okay grammatically, but means that you no longer want to go there. If you still want to go, then you can just use "want".

One of my favorite YouTube channels called Kevin’s English Room posted a video today, and in which they introduced a hamburger called baconator from Wendy’s.

I knew thehave heard of Wendy’s first, so I searched for it and I found that there isaren’t any shops around my area.

“I knew the Wendy’s first” doesn’t make sense I think “I know of Wendy’s/I have heard of Wendy’s/I recognize the name Wendy’s is maybe what you are trying to say?

I was disappointing….ed

It seems there are the shops in Osaka and Kobe, so I wanted to go there next time.

One of my favorite YouTube channels called Kevin’s English Room posted a video today, and in which they introduced a hamburger called bthe Baconator from Wendy’s.

I knew the've heard of Wendy’s first, so I searched for it and I found that there isaren’t any shops around my area.

It was disappointing….

Or "I was disappointed."

One of my favorite YouTube channel called Kevin’s English Room posted a video today, and in which they introduceding a hamburger called baconator from Wendy’s.

I knew theabout Wendy’s first, so I searched for it and I found that there isaren’t any shops around my area.

It was disappointing….

It seems that there are the shops in Osaka and Kobe,so so I wanted to go there next time.

The tense of the verb is wrong

One of my favorite YouTube channel called Kevin’s English Room posted a video today, and in which they introduced a hamburger called bthe Baconator from Wendy’s.

I knew theThat was the first time I heard of Wendy’s first, so I searched for it and I found that there isn’aren't any (shops) around my area.

I was disappointinged….

It seems there are the shopWendy's in Osaka and Kobe, so I want(ed) to go there next time.

We don't usually called fast food restaurants shops.

One of my favorite YouTube channels called Kevin’s English Room posted a video today, and in which where they introduced a hamburger called baconator from Wendy’s.

I think this is the most natural way to say this. Another approach which is closer to your original is:

One of my favorite YouTube channels called Kevin’s English Room posted a video today in which they introduced a hamburger called baconator from Wendy’s.

I knew theof Wendy’s firstalready, so I searched for it and I found that there isn’aren't any shops around my area.

If you'd like to keep shop singular, another acceptable way to phrase this is:

I knew of Wendy’s already, so I searched for it and I found that there isn't a shop around my area.

I was disappointing….ed…

We use three dots for ellipses

It seems there are the shops in Osaka and Kobe, so I wanted toill go there next time.