when a click the Play button a red line moves not the normal blue one and it doesnt render. the screen is also black
here is a pic https://i.gyazo.com/600ac0e7b2fc8bf1526f65917f78c5d2.png
First, please drag your screenshots to the reply field in this forum because it makes them much easier to see. Second, if you are having problems with a project you need to give us details and reveal the modified properties of the layers that are giving you problems by pressing the U key twice. Just a screenshot of your comp with no other info isn't very helpful. Last, if you are new to AE then you should let us know. If you haven't added some effect that is slowing things down or your system hasn't run out of resources most problems like the one you are describing are user error.
Try purging your image and disk cache using the Edit menu. Try saving the project and then restarting AE. If none of that works and you are using the latest version of AE and your system is up to date then give us details so we have some chance of giving you some help.