Screen have rainbow vertical and horizontal lines

First I’d try plugging it to an external monitor/Tv to make sure it’s just a screen issue. If that’s confirmed you got basically 3 options:

• get it serviced by Apple if you want an original new screen, that’s top quality and top price of course
• buy an original used screen and replace it yourself. That’s cheaper than Apple service, but it will be a used item with different grades available depending on overall condition. iFixit doesn’t have it in stock at the moment but you can find a replacement around usual market places.
• buy a new screen refurbished on a used or your own lid, there are refurbishers here and there who also supply the full screen install, or you can just buy and replace yourself the screen assembly.

I’d say between the cheapest to the most expensive option you’d have plenty of choices and you might have about 300/350$ difference in price.