I need a loading time optimization of an existing WordPress website with Woocommerce

For a current project I am looking for a web developer who is very familiar with WordPress. It’s about optimizing loading times for an online shop that works with woocommerce. The online shop has around 11,000 items and is fully operational. A clean and careful execution is therefore essential!
It’s about the online shop
https://www.kauf-dein-regal.de

Aims:
1.) There are two main goals to be achieved.
The values of the Google PageSpeedInsights test should be improved.
Currently: 42 mobile and 84 desktop
Goal: At least 90 mobile and desktop
2.) The actual loading time of the website should be improved.
The “DOMContentLoaded” value must be reduced. From the current average of 3.5 seconds to 2 seconds.