Optimize Shopify website through correction of Google Search Console issues & increased page speed

Description

Hello! We have recently upgraded our Shopify website and are using the "Flex Theme" from Out of the Sandbox. We are happy with the overall theme and design, however, we see technical areas that need improvement. We'd like to see optimization in site speed which is currently 27, as well as correction of items identified in Google Search Console, such as poor web vitals and page index issues. We are a small company and budget is limited. Due to this, we are open to a variety of structures that best fits the expert and us together. We are open to consultation work in which an expert can teach us how to correct issues fairly easily and we correct ourselves in between consultation calls.