the first one you go to jubilife city and beat him
the second one is at hearthome city
the next one is at pastoria city
thenext one at Pokemon leuge
and then at battle tower (tip)....... u can only battleur rivel at battle tower every Saturday and Sunday.
If by strong you mean higher level, the stronger trainer is your rival, which you can battle at the weekends at the Fight Area.
Your rival has a Munchlax. That's how he gets Snorlax. When you battle Mars & Jupiter at Spear Pillar, your rival teams up with you. If his Staraptor gets knocked out, he sends in Munchlax.
Your rival.
You can battle him at the end of victory road
You only have one rival (or do you mean the second time you battle your rival?)
Your rival will have a staraptor in the battle area
your rival will have one and so will you. A trainer will have the last one.
It matters what starter you choose
The rival the third time you battle him in survival area
Yes there is your rival if you pick Treecko or at battle hill after you beat the Elite 4
No, it is considered a normal Pokemon battle. Does your poekmon heal every time you get to a trainer? no.
hmm, first trainer battle had either a lvl 4 or a lvl 5.... Mine was 7 I think, got through just fine, snappy easy! That's the first trainer battle, ok? So, not much need to worry. First RIVAL battle is their highest poke should be lvl 9.