You asked an extremely intelligent question; but this is an intellectual mission that fell under the classification of the Ten Unexpounded Concerns, I presume. It belongs to this group: Is the world eternal?. Discerning that question, it is asking Does the world have beginning/When does the world initially appear; do the same, Who was the very first Buddha?
Given that the Buddha withdrawn from giving response to the Ten, usually that’s completion of it. And after that the classical way is to tension, Buddha’s mentor is for ending suffering … for somebody like injured by an arrow at heart passing away instantly … etc. and so on full-stop. Done.
However I think possibly you are interested to investigate a bit more …
The intellectual concerns are restricted by intellectual constraint. Intellectual limitation of acquiring concern or response is restricted in these 4 types:
- This is (P)
- This is not (-P)
- This is likewise is not (P likewise -P)1
- Neither this is nor is not (Neither P nor -P)2
Called Catuṣkoṭi, I choose the name “Four-statements”. Not a 5th declaration can be procured by the intellect, except combining the 4 to make sub-sets.
A concern asked from these Four-statements answered in the Four-statements, Buddha called it “video game of the mind” (戲論). There are a lot of these examples in basic teachings taped in Agama Sutras; advanced examples in advance teachings taped in such as Avatamsaka Sutra (the first Sutra spoken by the Buddha). For immediate, if this exact same kind of concern asked by a Christian: Who created the world? Ans: God. Who created God? Ans (perhaps:-RRB-): God’s daddy. Who created God’s dad? Ans: God’s grandfather … finally, one can just come up this answer to stop the question: God is Alpha and Omega (the start and end/no beginning and end). See? How dreadful the mind can elicit video gaming!
However, The Reality is beyond these Four-statements; beyond intelligence, beyond the mind; can be pointed, yet not caged for display screen, like the finger indicating the moon. That’s the deepest mentor of the Buddha. Nagarjuna elaborated the mentor exceptionally, for easy application, used one word: Vacuum (空).
OK. I’m diving a bit excessive into the sea, providing too long an answer, a bit scary too, huh? Better is learning on your own:-RRB- Now let’s go headlong into your title question:
Who was the very first buddha?
The brief answer is: 。 (silence)
Additional: The number of buddhas isn’t increasing nor decreasing … etc., for this example is a prolonged fabrication constructed by the Four-statements.
Now let’s deal with the next:
how did he become buddha without the dharma or a guru?
I think the he you referred to Buddha Shakyamuni. Initially, the Dharma is continuous and present, not produced thus can’t be ruined; the word used to refer is suchness, or thusness. By the moment Prince Siddhartha realized full enlightenment, he embodied the Dharma, by embodied the Dharma he realized complete enlightenment, called Buddha Shakyamuni.
Guru I think you implied instructor. Buddha’s instructors are previous Buddhas, among the most substantial Gurus for our Buddha, would be Buddha Dipamkara. To be the Lord Buddha of the Three-thousand-world (三千大千世界)3, one has to get the Mark (授記) from the previous Buddha. In Buddha Shakyamuni’s case, the Mark was endorsed by Buddha Dipamkara4. When a Buddha is completely informed, worth to be the teacher of all humans and devas, opens the deathless gate for all, he is called a Samyaksambuddha, one who attained the peak of enlightenment, Anuttarā-samyak-saṃbodhi. My other post may supply more information.
There is another kind of Buddha, he doesn’t have an Expert [to endorse him the Mark], called Pratyekabuddha, or called self-awaken Buddha (獨覺佛). He understands full knowledge by discovering the Dharma by himself, pondering the 12 Nidanas, during time there’s no Buddha appearing. He does not teach nor forming Saṃgha to continue any mentor.
Certainly your concern is well created, including comprehending numerous Buddhist doctrines. My response just works as signs, it’s for you to check out the richness of the Buddha Dharma, how Buddha sees cosmology, life, the world … and so on _/| _ (all-my-ten)
Footnotes:
1. From Chinese phrasing I believe it made more sense to utilize likewise then and. Certainly putting and is breaching logic.
2. It follows that the fourth statement should be treated same way.
3. Three-thousand-world has various meanings, I’m still unclear about the grouping of solar systems and galaxies how they described in Buddhist cosmology. My assertion is, either one galaxy one world, or one thousand galaxies one world. If it’s the later on, then 1,000 Milkyway-like star-clusters will be one Samyaksambuddha’s mentor ground ~ big class! Sources associated with one 3TW presiding one Lord Buddha: Agama Sutras, Avatamsaka Sutra, Mahāprajnāpāramitāśāstra, Abhidharma-kośa, and so on
4. Sources: in the Sutras gathered in one of the 12 Sutra-sections of the Chinese Canon, the Agama Section (which is equivalent to Pali Canon’s Nikaya Pitaka); Diamond Sutra, Dharmagupta Vinaya (made it through only in the Chinese Canon), Mahāprajnāpāramitāśāstra, and so on