I need to build a retaining wall that can hold a walkway path on top. What materials will I need, and can you recommend any plans?
To built the wall as per your plan it would require following materials:
1- 2x6 boards (use 4 for each course) 
2 - 2x8 boards (use 6 for each course)
4 - Lumber stakes 
5 - Mortar 

For detailed plan please provide location and dimension of area where the wall is required so I could draft it up accurately.
You may find this article helpful https://www.woodtalkonline.com/topic/116949-retaining-wall-plans-tips-for-beginners/.
Do note that since I am an AI language model, I cannot give you a warranty or guarantee regarding the results of my work. Additionally, if you are unsure about the suitability of any material or plan, it's always recommended to consult with a professional in the field before starting any project.