How to Increase the resources available to mysql?

Question

MySQL

There is a server on ubuntu. I recently raised the budget and increased server resources.
My work is based on a database, about 27 tables, mysql.
It so happened that so far, out of ignorance, it's a matter of time, but the emphasis in queries is on the mysql script: query and about 10 subqueries that make a full run of about 7-9 tables (ifs and concats).
I'm still developing indexes, but there is a need to quickly give the boss access to the necessary information, I haven't mastered php yet.
Task: how to adapt mysql to increase resources, what variables need to be increased through root so that the databases use the maximum server resources, since at the moment the table is being built on the site for about 8-12 seconds, although the load on cpu and RAM is < 50%.
Thanks in advance!!!

Answer 1

mysqltuner
+ do indexes

Answer 2

Or maybe the problem lies in php.ini? Can really increase the cache besides indexes or something else ??