Please can you suggest me a few audio book sites (some free as well if possible )?

Audible has about 50 freebies on the site at all times.

We have a couple other audiobook threads here.

Don't forget Librivox.

Great Humble Bundle on audiobooks.
https://www.humblebundle.com/morebooks

There's a groupon for two free months of Audible, worked for me even though I just cancelled a different free membership. And audible has a 2 for 1 sale with some great selections right now, so 3 books for free.