I pretend I am a PD. I will make an educational program. I will call it "Let's Learn Japanese". I need two native speakers and a Japanese teacher.

With the help of the nateive speakers, the teacher can make a good textbook.
The native speakers can talk with each other on the program. The Japanese teacher can explain Japanese expresions in Korean. This program will be very helpful for people who want to learn Japanese.

(Would you read the passage and check the errors? Do we have to use 'the people whe...' or 'people who...'?)

I pretend I am a PD<~~Will your readers/listeners know what this abbreviation means?. I will make an educational program. I will call it "Let's Learn Japanese". I need two native speakers and a Japanese teacher.

With the help of the native speakers, the teacher can write a good textbook.
The native speakers can talk with each other on the program. The Japanese teacher can explain Japanese espressions in Korean. This program will be very helpful for people who want to learn Japanese.

(Would you read the passage and check the errors? Do we have to use 'the people whe...' or 'people who...'?)
Either expression is fine, in this case. I don't see any real difference between the two.

Sure, I can help you with that! Here's the corrected version of your passage:

"I am planning to create an educational program called 'Let's Learn Japanese', where I will play the role of a program developer (PD). To develop a comprehensive textbook, I will need the assistance of two native Japanese speakers and a Japanese teacher.

The native speakers will have conversations with each other, which will be included in the program. Meanwhile, the Japanese teacher will provide explanations of Japanese expressions in Korean, making the program more accessible for learners. I believe this program will be extremely valuable for those who are interested in learning Japanese."

Regarding your question about using "the people who" or "people who," both variations are correct in different contexts. However, in this case, it is more natural and concise to use "people who" instead of "the people who." It is because we are referring to a general group of individuals, rather than specific individuals who have been mentioned previously.