Welcome to the Plone communit, @kigh143. We are glad to hear from you, and grateful for your interest.
In general, Plone follows a fork-and-pull method for fixing bugs. You can fork the repository where the problem is located, write a test that demonstrates the bug by failing appropriately, make a fix that causes your new test to pass, and then open a pull request back to the original to submit your work.
You should read our documentation on core development, which @tkimnguyen has linked, to learn about the tools we use to develop Plone, and to get the contributor's agreement we will need you to sign.