Yes if you chose charmander as your starter your rival will get a venusaur when you battle him at silph co.
One of the trainers in Victory Road will have one.
Unless you have chosen a Bulbasaur or a Squirtle as your starter Pokemon, seeing a Venusaur in Pokemon Red is very difficult. If your starter Pokemon is a Bulbasaur, you will see a Venusaur when it reaches level 36. If you chose Squirtle, your rival will have a Venusaur by the time you reach the Pokemon League. Very few (if any at all) Pokemon trainers will have with them a Venusaur. The closest you will get is an Ivysaur which some Grass-type trainers will carry with them. your best chance of encountering a Venusaur would be to trade or battle with a friend over a link cable.
Your rival will have a Venusaur if you chose Squirtle as your starter.
Your rival will get a venusaur only if you chose squirtle as your starter i believe he will get one when he is at silph co, other than that to see or get a venusaur a friend with firered or leafgreen needs to give you one.
No.
You can't catch Venusaur on Firered, but you can get Venusaur by choosing Bulbasaur as a starter then training it. You can trade it (from someone who chose it as their starter) or you can use AR or Gameshark to catch one. If you know someone who chose one as their starter but don't wanna give it away you can ask them to breed it with a ditto and give (trade) you the egg. It will hatch into a bulbasaur =)
Venusaur, since its a starter. Or Victorybell.
one of the people in victory will have one though your starter is charmander
your starter Pokemon can handle it if they are blastoise, charizard or venusaur.
You can have a friend trade you there starter Pokemon the cool thing is if you breed your starter you can have a bunch of starters for example if you have a venusaur you can get a bunch of bulbusaurs.
If you chose Charizard then there is no way to get venusaur unless you have an AR or you trade from another game. I suggest trading from another game if you can just because it will grow quicker.
It evolves from Ivysaur at level 32. Just choose Bulbasaur as a starter Pokemon where it's available, evolve it to Ivysaur (it evolves at level 16), and evolve Ivysaur into Venusaur.