Previously, this was an industrial area occupied by a giant automobile manufacturarer for almost a century.

However, ten years ago, the company gotwas liquidated, and this areal was gradually transformed into a fancy premium class neighborhood.

Recently, a new private museum of contemporary art was grandly inagurated, becoming the cherry on the top of this district and attracting myriad of art and architecture lovers (such as me).

Previously, this was an industrial area occupied by a giant automobile manufacturarer for almost a century.

However, ten years ago, the company got liquidated, and this areal was gradually transformed into a fancy (premium class/luxury) neighborhood.

"class" with neighbourhood is very strongly associated with social class (e.g. upper class, middle class, working class..) so using it with a different adjective like premium sounds unnatural. You can just use premium as an adjective directly for neighbourhood, or luxury I think would be a little more common here.

Recently, a new private museum of contemporary art was grandly inagurated, becoming the cherry on the top of this district and attracting [myriad/many] art and architecture lovers (such as [myself/me]).

The "me" in "such as me" is pretty casual language, while "myriad" is very posh sounding language and they kind of clash a bit when used in the same sentence. I think "myself" goes better with "myriad" while if you're going to keep "me", then it's better to go with "many".

Hence, in the next couple of decades, the edifice will turn (turquoise/green), like The Statue of Liberty did.

I think most people would describe the colour of oxidised copper as green, rather than as turquoise.

Previously, this was an industrial area occupied by a giant automobile manufacturarefactory for almost a century.

I am choosing the corrections I like best from those you have received ;)

However, ten years ago, the company gotwas liquidated, and this areal was gradually transformed into a fancy premium class neighborhood.

No need for the passive voice "was transformed."
So, here is the deal. You can use "premium" as an adjective directly in front of the noun it modifies.
If you want to talk about "class" then the most common modifiers are "upper" or "high." All options are good in this context, but I don't think you need "fancy" with premium. Your call.

Every building there has some unique traits, so just wandering around and exploring the area becomes veryis interesting.

Edit to keep sentences direct and to the point, and you will write clear vigorous English.

Recently, a new private museum of contemporary art [was grandly inagurated], [becoming the cherry on the top of] this district and attracting myriad art and architecture lovers (such as me).

"Grandly inaugurated" sounds unnatural to me. I would experiment with "opened with great fanfare" or "had a grand inauguration" or some other combination.

There is nothing wrong with the idiom "becoming the cherry on the top of this district" conceptually, but it is a mismatch to use a food analogy here, imho. I offer you "the jewel in the crown" as an alternative that matches the topic and your style.

Most if its imposing buildingfacade is made ofrom copper, a material that, as you know, gradually changes its coloring due to the oxidation.

I love this correction. "Facade" is perfect here, and I would not have thought of it. No need for "the." (It is similar to saying "due to aging."

Hence, in the next couple of decades, the edifice will turn turquoise, like The Statue of Liberty did.

I think it works just as well without "did," and it gives a timeless or ongoing quality to the process if you omit that word.

Previously, this was an industrial area occupied by a giant automobile manufacturarer for almost a century.

However, ten years ago, the company got liquidated, and this areal was gradually transformed into a fancy premium upper-class neighborhood.

Every building there has some unique traits, so just wandering around and exploring the area becomes very interesting.

You have been using "this [area]" so far, so "here" is more natural. If you had been using "that" instead, then "there" would be fine.

Recently, a new private museum of contemporary art was grandly inaugurated, becoming the cherry on the top of this district and attracting myriad art and architecture lovers (such as me).

Most if its imposing building is made from copper, a material that, as you know, gradually changes its coloring due to the oxidation.

Perfectly OK, but if you're referring to specifically the exterior of the building, you might find "facade" a more specific word than "building".

Previously, this was an industrial area occupied by a giant automobile manufacturarefactory for almost a century.

However, ten years ago, the company gotwas liquidated, and this areal was gradually transformed into a fancy, premium class neighbourhood.

Recently, a new private museum of contemporary art was grandly inaugurated, becoming the cherry on the top of this district and attracting myriadany art and architecture lovers (such as me).

Most iof itsthe imposing building is made from copper, a material that, as you know, gradually changes its colouring due to the oxidization.

Hence, in the next couple of decades, the edificebuilding will turn turquoise, like Tthe Statue of Liberty did.