Database Tuning to address poor performance

I'm not a DB Administrator but am looking for advice on tuning our MySQL database. It's a small storefront that is running Prestashop, and lags out for several minutes when saving changes to a product pack. That is, a product that is made up of 2 or more other products. I just ran MySQLTuner-Perl and it looks alright for the most part, but there are several points flagged for review. [!!] Aborted connections: 6.83% (337899/4948004) [!!] CPanel and Flex system skip-name-resolve should be on [!!] Joins performed without indexes: 10213707 I suspect the 10M Joins performed without indexes is the likely culprit here, but not entirely sure what that means or how it should be addressed. The server has tons of spare memory so I could increase the allocation 2-3x as a temporary bandaid, but I imagine this won't be resolved until I figure out the indexing issue. Any advice or clarity on these results would be greatly appreciated.