why is Google still popping up on Firefox

If you mean Google keeps coming back as the default search engine, I would first check Firefox Settings → Search → Default Search Engine. Also check your extensions. Some extensions can change the default search engine, so disabling a suspicious extension can fix it. If Google only appears in the search suggestions, that's different. Google can still be listed as an available search engine even when another engine is your default. You can disable it from the Search settings if you don't want to see it.