How can I reuse a helper class like project?

Actually my problem is that EVERY solution is still an option. I’m new at my current job and looking for the best way to streamline code production. I have just about all the freedom in the world, I might even get a budget if I ask for it, but for now I’m trying to achieve it without extra costs.

I am starting to understand that using something like a local maven is probably the best way to go (I came across artifactory, maybe this is something we can use) and have asked a new question about how to best implement my helper project to build jars for that: Multi project jar generation