guitexture is obsolete use ui.image instead code example
Example: error CS0619: 'GUIText' is obsolete: 'GUIText has been removed. Use UI.Text instead.'
/*Add at the beginning of the code:*/
using UnityEngine.UI;
/*then replace GUIText with Text*/
/*Add at the beginning of the code:*/
using UnityEngine.UI;
/*then replace GUIText with Text*/