Indeed, there are a lot of tutorials out there that cover building content for UE4. If you wanted to make a basic shooter, this website has it totally covered: shootertutorial.com
There won’t be any tutorials that compare UT99 with UE4 - we’re four engine revisions and twenty years ahead now. It’s better to assume that the two are completely different engines; whilst some terminology has remained, they are largely fairly different under the hood.