Trying to learn C with MorphOS SDK examples is like learning to ride a dragster motorbike without even prior knowledge of what a bicycle is.

As a prime starter, you should grasp the grammar of the C language.

http://www.learn-c.org/

Followed by how to build binaries with makefile

http://mrbook.org/blog/tutorials/make/

Once you've done this two steps, you'll know how to ride a bicycle...

Those two links are just kickstarter for the subject. There is tons of well written tutorial or ebook out there. Dig, read, experiment.

Once you feel a bit more confident with C & makefile, you can go one step further: learn what's specific to MorphOS by reading excellent krashan's tutorial on MZ library.

http://library.morph.zone/First_steps_in_MorphOS_programming

and the following articles.

Once you've done that, it is time for a first application.

Start with something simple and 'straightforward' like a tic tac toe game for example.

Feel free to ask for help here. Most MorphOS Team members kindly help when technical programming topics are posted.