You want to conduct the scientific method on the religion, which is good. In preparation for your reply, I read from 6 religious scripts (with internet help) and found that 3 of them encourage this exact approach, ordered by brevity:
John 7:17 (Christianity)
Kalama Sutta:10 (Buddhism)
Alma 32:28-43 (Mormonism)
The other three I read from (Quran, Bhagavad Gita, Torah) might also encourage this approach, but I didn't find the passage. If you are willing to read the verses around Kalama Sutta 10 paired with the test described in Alma, I think that is a 'complete' set of instructions for starting. This complete picture is in the NT too, but split across several books and not beginner friendly.
John 7:17 (Christianity) Kalama Sutta:10 (Buddhism) Alma 32:28-43 (Mormonism)
The other three I read from (Quran, Bhagavad Gita, Torah) might also encourage this approach, but I didn't find the passage. If you are willing to read the verses around Kalama Sutta 10 paired with the test described in Alma, I think that is a 'complete' set of instructions for starting. This complete picture is in the NT too, but split across several books and not beginner friendly.