This is a guide steps you should take with any new wordpress installation. Always avoid using excessive plugins when possible. Remove any unused plugins.
CREATE A BACKUP FIRST.
1. Go to your cPanel >> backups, Create a home directory backup and download it.
2. OR go to your cPanel >> File Manager >> Compress the public_html folder. Download. Then go to phpMyAdmin >> Select The Database >> Export >> and Download the .sql file.
3. OR download Updraft or Backup Guard and create a backup within the plugin. This doesn't always work for large WP's on shared hosting *It will create a backup but might be too big to upload.
Run GTMetrix and Pagespeed Insights to track your progress.
1. Google Analytics. Always set it up, if your not tracking your performance you don't know what your site is doing. If your theme option you can add the ID within there. Go to analytics.google.com then Admin >> then add a new account. Copy the JS include script. Go to Appearance >> Editor >> Then find the header.php Copy and paste it in the top of that file. This will save you from querying an extra plugin or database call.
2. HeartBeat - Install heartbeat plugin. Under increased users wordpress heartbeat refreshes too often causing the site to slow down considerably.
3. Image Compression- Install Smush plugin. Go to Media >> Bulk Optimize. Smush until done. This will run on any server without using phpexec.
3b. More Image Compression-Install Kraken plugin. Register for an account and set up the authorization. Confirm your signup email, then in API add the Key and Secret to the plugin. Go to Media >> Library >> select the LIST VIEW option. >> in Bulk Settings dropdownn click "Krakem all". Do this for each page of images. It's almost always worth it to select lossy compression, the quality reduction is often non-noticeable and the savings worthwhile. This process runs remotely and will run on any shared server as well.
4. Install W3 Cache. It is much faster than supercache but a little more tricky to configure. After installation go to Performance >> General Settings >> Select Page Cache, Minify (Enable with defautl settings) , Database Cache, Browser Cache.
-Toward the bottom- Turn off The page speed dashboard, rewrite rules, and all other options. Then enable Edge Mode. -MAKE SURE DEBUGGING- is not checked. This would slow the site down.
Increased Performance on especially image heavy sites, sign up for MaxCDN for $9/month and enable it in Performance >> CDN. You will have to set up a zone in maxcdn, then in Settings >> Account >> API. Copy the Alias+ID+KeySecret. Then copy the Cname into the maxcdn settings in W3 CDN settings.
5. DB Optimize - Install WP Optimize plugin. Click Run all Optimizations in the plugin. This will also clear out your old post revisions- so if you need them don't optimize those tables.