Have you definitely got a micro USB? If not you need one. Either it's not a Micro USB or you've got a loose cable. If you are trying to transport data from your phone to your PC, try MyPhoneExplorer.
Re: whn connected chromecast does not show homescreen?
I had this problem. I fixed it by going behind the TV, checking it is plugged in properly. If not, go onto the official Google Q&A and they should help. :)
Re: Headphones do not fit in jack properly
You may need to buy an adaptor on amazon. If there are non, you may need to use other headphones. A-Jays are designed for MP3s like sandisks. Sorry there isn't an official answer. Just my suggestion.
If you are using an Android, install an app called ES File Explorer. Go onto the app. Go into Home, Pictures, Screenshots, hold down on the screenshot you want to delete, and move it into the recycling bin. Hope I helped :)