Here is a guide: heal pikachu at a pkmn center and use some potions on him(the potions wont work, but they make pikachu happy)Then, once you see hearts on top of his head, go talk to the girl in cerulean city and you got yourself a bulbasaur!And for digletts cave, you should clear it, by entering from vemillion city and you find yourself south to viridian city.Go south, untill you find a cuttable tree.Cut it and go further.You will see a gate.Enter it and Proffessor oaks aide will give you HM 5, once you have 10 pokemon in your pokedex.You also could go to the route south of viridian and cut the tree near it.There also is a boy, that will trade you a dugtrio for lickitung.lickitungs are only found in victory road and dugtrio is easily evolved from diglett, so dont trade.however dugtrio is an outsider and once you trade, you can have a dugtrio, that will obey every command from you.(you wont lose the pokedex entry after you trade).