Would like to learn how to best use AI to do code completion as well as create full stack websites

Hey, I lost the rhythm for coding as I transitioned to product management role. Currently, I am working on a software product of building atleast the frontend with AI. What solutions would you recommend for an optimized code directly creating a clone such as this Plenty (https://www.withplenty.com/). Is there a platform which create the frontend as it is? I know no code tools but not considering that. I stumbled upon this site (bolt.new project) is it accurate enough to create the website on user prompts. What prompt does a user has to enter in accurate and correct way to get the desired the result? Also recommend me between Deepseek or ChatGPT? Also where I could develop a full AI model like a personalized investment recommendation system and a blockchain app with some integrations.