1. Show Hidden Files

.htaccess file is responsible for the Apache's core functionality, but you can't even see .htaccess file in your cpanel directory?
You need to check: "Show Hidden Files (dotfiles)"

Click the "File Manager" link

Click on the "Settings" at the top-right corner

Check the "Show Hidden Files (dotfiles)" 

2. Select fresh PHP version

Click the "Select PHP Version" link

and select the latest PHP version

Now your site will be approx. 2x faster, check php5 vs php7 comparison

3. Enable GZIP compression

Click the "Optimize Website" link

Check the "Compress the specified MIME types." radio button

in MIME types textbox enter: "text/html text/plain text/xml text/javascript text/css"

You will be tempted to check "Enable all content", but don't - it would only slow down your site because apache will get busy compressing already compressed image files

4. Force https 

add to .htaccess file:

RewriteEngine On

# force https
RewriteCond %{HTTPS} off
RewriteCond %{HTTP_HOST} !localhost
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

5. Change upload_max_filesize 

Add the following line to the .htaccess file( if php.ini is not accessible ):

php_value upload_max_filesize 8M
php_value post_max_size 8M