Definitely pick Bulbasaur. Bulbasaur rocks the first two gyms and resists Electric. By the time you get to Erika, you might've already gotten something to counter her such as Pidgey or Vulpix. A good way to deal with most strong trainers is to set up Leech Seed and poison to chip away at their health and Bulbasaur gets access to those moves pretty early. If you picked up anything else, I would suggest a Pidgey due to how fast and strong Pidgeot is plus it's good against Erika. If there's anything to worry about, it's definitely Sabrina. It's so easy to get sweeped by her Alakazam and there aren't many counters. Just hit it as hard as you can with physical attacks to kill it as soon as possible. Giovanni might also be an issue as well as Fuschia Gym's exploding Koffings. Try to catch a Snorlax since it has plenty of bulk to tank an Explosion or Self-Destruct. Other than that, make absolute sure you have the right levels for any major battle such as the gym leaders or Elite 4. If not, go to the day care and grind as much as much as possible (or just grind to around their level if you're trying to keep it fair). Other than that, the rest is up to luck and skill. Good luck
