Hilary here from Shopify Support. Welcome to the Shopify Community! I'd be happy to make a couple suggestions here for you from our Shopify App Store:
1. Ablestar Bulk Product Editor
2. Bulk Product Edit & CSV Import
Let me know how these recommendations go! I'll pass on our Help Center article on the Google Channel Requirements. It explains the requirements for your store, Google account, products, and shipping. Google requires different pieces of information depending on which category your products fall into. I recommend running through the Specific Google Product Category requirements to determine what is required for your products before publishing.
Out of curiosity, are you planning on running any Google Smart Shopping campaigns for advertising? This is a great paid advertising option that can help you to promote your products and increase traffic to your online store. If you are already doing this, how have your campaigns been going?
Take a look at Mixtable. Mixtable is a spreadsheet like Google Sheets, but with all Excel-style formulas and behavior. And it seamlessly syncs to and from Shopify. You can easily change the fields you need in order to bulk edit your Shopify store's data, and then sync your data back to Shopify.