I had an iphone,a relative gave it to me from US..i deleted all the media and data in it,now i cant open it.it was displayed on the screen a figure of an apple with a working bar..is my iphone damaged already?how will i open it back?thanks

If you are planning to buy an iPhone, then you will get big surprises from the new iPhone, as it equipped with plenty of wonderful new features, such as facial recognition, wireless charging, etc.
And the new iPhone will be released alongside the latest iOS version - iOS 11, which also comes with lots of wonderful new features and improvements, including Do Not Disturb Driving mode, person-to-person Apple Pay, etc.
To get more details, you can visit Things that iPhone Can do the Android can't to have a better understanding of both iPhone and Android, then make you final decision. 6 Key Things What Can An iPhone Do That An Android Cant

Which kind of files you cannot delete from your iPhone? Synced photos, music, contacts or anything else? Here is a guide about how to delete synced photos from iPhone, hope it is helpful.
How to Delete Photos from iPhone iPad Photo Library Easily

Step 1. Just go to your iPhone home screen, and find the app you want to remove.
Step 2. Don't open up it. Press the app icon for few seconds until it wobbles.
Step 3. Now you should see a "X" icon on the top left hand corner of the app. Tap on it, and confirm you want to delete the app.
How to Delete Apps from iPhone iPad

If you did not backup your iphone with iTunes or iCloud , the recovery software for iPhone users may help you retrieve the deleted data, you can get them back in few steps.
Tips to Retrieve Deleted Voice Memos on iPhone 6 5S

So which kind of phone are you using?
If you are using an iPhone, I can help you figure it out.
Way 1: retrieve pictures from iPhone with iTunes backup file
1. Connect the iPhone to the computer with a USB cable.
2. Open iTunes.
3. If you have a new or erased iPhone, iTunes will prompt you to restore from backup.
4. Otherwise, Control-click on your iPhone under DEVICES in the left menu.
5. Select Restore From Backup...
6. Choose the backup you wish to sync and click the Restore button.
Way 2: recover photos from iPhone with iPhone data recovery program.
Read more: how to retrieve deleted pictures from iPhone with Macgo Mac iPhone Data Recovery

Before finding ways to restore or find back your contacts, you'd better to have a look at your Android device, because your contacts might not be deleted. So you need to make sure all your contats are being displayed.
Let's check it as follows:
1. Find "Contacts" and open it on your Android phone.
2. Tap on the menu button on the top right corner. Then choose "Settings" > "Contacts to Display".
3. Select "All Contacts". Now, you can return and check whether you got your contacts back or not.
An excellent program is required for the task - MobiKin Doctor for Android (Win/Mac). It is easy to manage as you can recover lost, deleted, or formatted contacts on Android phones through only several clicks.
How to Recover Deleted Contacts from Android? Step1: Run the Software and Connect Your Phone to Computer
Step 2: Scan Contacts Deleted on Your Android Phone

Step 3: Preview and Retrieve Android Contacts Selectively
A YouTube Guide for you:
How to Use MobiKin Doctor for Android

Firstly you have to plug your iPad into Computer and open a iTunes .

After that you can locate a iPad on the left side of the screen and click to the "device" menu .

Then right click on the name of iPad and click to the recover files and select a summary option which is inside a dialog box .

After that place a check mark next to the "Encrypt iPad Backup".

Now you have to enter a password and click to the set Password.

Then plug your iPad into Computer and choose a 'edit" option.

Now you can recover deleted message from Apple iPad.

Hi
Try resetting your phone.But remember this will delete all data and third party applications on your phone restoring its original/factory settings.Here's a video on how to.