Q: help in updating my system from 10.7 to 10.0

Hi. This article will be useful for you. How to update OS X and Mac apps - Apple Support

Some older MBPs cannot have a newer OSX installed than Lion.  Open System Information>Hardware and look at the MODEL IDENTIFIER.  If it is 3,1 or higher, then you can install El Capitan so long as the MBP meets these requirements:

https://support.apple.com/kb/SP728?locale=en_US

Ciao.

You should have no problem installing El Capitan.  Use the link provided by D.Cohen as a guide.

If you do install El Capitan, I would urge you to install additional RAM (8 GB total).  The newer OSXs like to use a lot of RAM.

Ciao.

Good luck. 

Ciao.

The HDD in your MBP has a problem.  Boot into the recovery partition and from the 4 option menu select Disk Utility.  Run Disk Utility>First Aid>Repair.  If the disk cannot be repaired, you will have to install a replacement HDD.

https://support.apple.com/en-us/HT201314

Ciao.