Fix Wordpress Caching Issues

I have a WordPress website on CentOS VPS.

WP Version: 5.9.2 (latest)
OS: CentOS on VPS -- No Cpanel
Web Server: Nginx
CDN: Amazon Cloudfront
Theme: RankingChamp
Caching Plugin: WP Fastest Cache (Previously, WP Super Cache)
Speed Boost Plugin: W3Speedster Pro
Other Imp Plugin: Contact Form 7

Requirements:
1. Clean implementation of Caching plugin
2. Remove multiple calls to Font-Awesome from source code

IMP:
- Contact Form 7 works & UI works perfectly (before I messed up Caching plugin last night). Ensure nothing breaks
- Current PageSpeed Insight Score: 93/99. Maintain the same or get better speed.

Budget: $50 - $100