My bedroom is huge, there is a big TV, a desk, a bed and three plants.
--- Do I need to use "there are" in the example above or "there is" is fine?
I would use "there is". However, you have a comma splice error there. The first comma is wrong.
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I would use "there is". However, you have a comma splice error there. The first comma is wrong. Use a full stop (period AmE) instead.