@jnsereko , Thanks for expressing in this Project.
i hope you went through GSoC 2020: Warm up practices for students.
Now initialy this project aimed at Upgrading Spring ,Hibenate ,and Java.
But ideally that would be too much to achieve in that short time .
Now it primarily requires upgrading Java from 8 to 11.
you would need to understand a few API changes from java 8 to 11, see this blog and this .
You also need a fundamental understanding of the OpenMRS core API