I ran various Challenges:-

1. I got many errors when I import the external libraries into my project. it is giving [android.support.v4.app.INotificationSideChannel found in modules core-1.5.0-runtime (androidx.core:core:1.5.0) and support-compat-26.1.0-runtime] which I solved by adding this to every dependencies except default dependencies[{
   exclude group: "com.android.support", module: "support-compat"
   exclude group: "com.android.support", module: "support-media-compat"
   }]
2. when I used URI library I got this one [URI is not registered (Settings | Languages & Frameworks | Schemas and DTDs) in applicationContext.xml] which is very iritating while write code since it gives the red color that scares me ,
   I solved this by[Since this is in IntelliJ IDEA . If you place the cursor over the URL (or select it), a red bulb on the left border of the window. That red bulb, when clicked,it will give me some options to correct any errors. One of the options is to download the DTD (Fetch external resource)] and clicked it.
3. when I am add an toolbar with the help of [setSupportActionBar(binding.toolbar)] , I ran into this error that kinda freaks me out which I am not getting how to solve [Do not request Window.FEATURE_SUPPORT_ACTION_BAR and set WindowActionBar to false in your theme to use a toolbar instead] the searched in google ; after a lot of searches I finaly got the solution to stack overflow ie[ <item name="windowActionBar">true</item>
   <item name="windowNoTitle">true</item>] I added this to my theme.
4. [Android gives error “Cannot fit requested classes in a single dex file”] this error got me a headache finnaly after a lot of searched i got the solutio[implementation 'androidx.multidex:multidex:2.0.1' add it to my dependencies , and adding it to my build.gradle multiDexEnabled true]
5. [String too large to encode using UTF-8 written instead as 'STRING_TOO_LARGE'] I solved by deleting some drawables.
6. I ran into other silly errors.