Why is my screen get lines

@faizan67985 you are not giving us enough information. OR at least you could post a picture of what your phone screen displays. Check this guide How to ask a good question on iFixit and see if your can rephrase and add information to your question. iFixitでの質問に画像を追加する方法

Here is a generic answer to a very generic question, you need a new display.

Since there are no guides on iFixit that show the LCD replacement, I suggest that you use a video like this It will get you there as well. Replacement screens are widely available so you do want to do an online search for that to find what you like. Just remember that there are 2 versions of the A13 so make sure you get the right one for your phone.

While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.