What is the first real obstacle that phoenix encounters?

The first real obstacle that Phoenix encounters in "A Worn Path" by Eudora Welty is the physical challenges of her journey through the rugged terrain. As she navigates the path to obtain medicine for her sick grandson, she faces barriers such as a steep hill and a wild dog, which symbolize the difficulties of her aging body and the societal obstacles of her race and poverty. These challenges test her determination and resilience, highlighting her unwavering love and commitment to her grandson.