The parent without any involvement from the school district issues high school diplomas for children who have been homeschooled; therefore, the district or state graduation requirements do not apply, only those of the parent's choosing.
The number of courses a home-schooled child completes to obtain a diploma is entirely up to the parent, but an average amount would be between 19 and 23 with a minimum number of courses taught in each subject.
If a home-schooled child wishes to gain admittance into college after graduation, the course requirements should be more stringent and include 24 or more credits.
While it is not technically a requirement to record a grade point average for home-schooled students, it provides for more accurate and credible credentials when they are ready to further their education.
It is not necessary for a home school diploma to be accredited, but for those wishing to do so there are many reputable companies online that can aid in the process of providing one to you.