1. Is following Tajweed rules wajib while reciting the surahs and dhikrs in Namaaz ?

2. What If one doesn’t know the tajweed rules and has been reciting namaaz?

3. What is the ruling for youngsters , old people and newly converts who don’t know about tajweed rules?

Tajweed is not wajib, what is required is proper recitation of the Arabic