Q: Can I download OS X El Capitan on my MacBook from 2010?

Your computer is new enough to install El Capitan, but you need other prerequisites that you have not told us about.

In particular, you need at least OS X 10.6.8 currently, and at least 8.8GB of free space on your storage device.

Upgrade to OS X El Capitan - Apple Support

It is compatible if you have enough RAM and disk space. OS X El Capitan - Technical Specifications

If you meet all the prerequisites, and are stuck in a loop having to do with resuming a partially download installation file, then you should go to your Applications folder, and search for and delete a file called "Install OS X El Capitan".  That would start your download over again from the beginning.