Is there any way to pin phone number dial on start? (It should look like windows icon>dial phone number icon>dial number>call)
You cannot currently have a one-tap speed dial direct from the start screen. This is possibly by design to prevent accidental calls.
However, you can pin a particular contact to the start screen and then it's tap to open, tap to dial.
Windows Phone 8.1 has a speed dial section on the Phone app. There you can group and arrange all your commonly called numbers for one-tap access.