Wordpress site speed improvement

I need a Wordpress developer that can fix my website performance and load speeds. Current load times are not acceptable in order to retain customers.

My site uses the Avada Theme from ThemeForest, with the WooCommerce plugin to power my e-Commerce site. Based on the GT Metrix tests below, I need someone that can work on the specific issues identified, and also identify any other areas of improvement. As a minimum for the speed issue, I would like all elements to be green on the GT Metrix tests.

I would also like to understand how to best optimise images for my website going forward (especially for my products).

Home Page:
https://gtmetrix.com/reports/bernardpretorius.com/Rq3UDar1

Products Landing Page:
https://gtmetrix.com/reports/bernardpretorius.com/V2HqPCfu

Individual Product Page (example):
https://bernardpretorius.com/product/converging-waters/



Fixing the speed issue is number one priority, once that is fixed I would also like some help with fixing cosmetic things:

* Homepage - Icon backgrounds to be the same colour as the page background

* On the Prints page I have a sidebar to the left for customers to search and also select specific categories. However, once you have selected a category it disappears - how do I fix this?

* On the individual products page the plus and minus icons to select the quantity is white - I would like it to blend more in with the rest of the site.

* About me page - the parallax scroll image quality is really poor, despite the uploaded image should be fine.

* Mobile view - how can space the site logo and cart / search icons more appropriately