Leverage Browser Caching won't work

Hey! I’m kind of new to WP, and don’t know much yet.

I have a website running

https://www.luizcarlosestoque.com/wordpress

it’s suposed to be a Car Dealing website, with lots of cars exposed, so the loading speed must be good for the site to work. But it’s loading too slow.

Running page speed tests, i’ve realized that my bigger problems are with Browser Caching.

So I started browsing and installed Leverage Browser Caching Ninjas Plugin. It’s activated and running, but nothing changes, speed tests keep on showing many files with “expiration not specified”.

So I added all the codes like ExpiresByType image/jpeg “access 1 year” on .htaccess, but still, nothing happens!

My main kind of files are like this, on the test, it shows a lot of it:
https://luizcarlosestoque.com/wordpress/wp-content/uploads/2015/05/chevy-logo.png (expiration not specified)

I’m here to listen any suggestions you guys can make, thank in advance!!