Creating a similarity app for a search engine

I am working on similarity app for a search engine it is like a recommendation system but based on the product characteristics and not on the user history
It is an eCommerce search engine that work on multiple categories example high tech and each one is containing sub categories
I though on a clustering model based on features and after that a classification problem related to the crawl to classify the new item based on the clusters(edited)
I am debutant in ML
thanks for the help