You chose a Fire starter, yes? I did the same thing. (I always do.)
I did trade for a Snivy and an Oshawott as well (I traded Eggs produced by some of my Pokémon), but a Deino can be found on Victory Road when you get there. It's already fairly highly-leveled so you don't have to spend time training it to get to that starting point. What stage in the game are you at? If you have reached Nimbasa City and freed the Day Care Man from Team Plasma, he will give you a Bike; after this point, you can put compatible males and females in the Day Care together and breed. After some jogging back and forth the Day Care Man calls you over and gives you an Egg, which you can then either hatch or trade unhatched for something.
If you want to make it interesting, look up a Pokémon's article (here for example is Tepig) and see what Egg Moves they can use, and breed using a male with that move. Using Tepig as an example, I have a Lv.1 Tepig in my box with Superpower and Thrash, and another with Yawn which already knows Fire Blast (Eggs of those were used in the Snivy/Oshawott trades, and they also had Egg moves). Trying your hand at breeding can produce something someone might want to train themselves or at least offers them some trading material. (Note when breeding that if five moves could be assigned to a Pokémon, the move in the first slot gets replaced, so switch around the female's moves so the move you want KEPT is last in order to ensure it's not covered by another; learned TM moves can and will be passed down if the baby can learn them.)
Myself, I could come up with a Snivy and an Oshawott, and even a Deino, but unless you want an Egg Move you're better off catching your own and grinding it on Audinos before the E4; it would take a LOT to get Hydreigon until you get to the higher-leveled ones on Route 11, where I finally evolved mine. It's more rewarding to catch it yourself and train it. However, in the case of the starters, yes you have to trade and if you give me some time to do some breeding it might be possible for me to come up with something. Meanwhile, look up their articles as above (they're clickable in the Tepig article in fact) and see if you want a certain Egg Move. If I can't produce that, I'll tell you. In the meantime, how about some Eggs from your Day Care that are something I haven't seen before? For inspiration, I have Gothita (Black catch only) with Miracle Eye, making Psychic attacks usable on Dark types like Purrloin; I also have Vullaby (also Black catch only) with Roost. And yes, I can breed a Rufflet and Solosis if needed; I got these from a White player and can breed.
The only complication is I don't know when we can meet up to trade. I head out to do any trading and sometimes the connections don't work as well as I'd like. Never will try at a McDonald's again, but I found two eat-in restaurants that work well. I tend to trade from those.
EDIT: I do have a fully evolved Swellow as well - I caught two by accident and can trade one of those if you want it. You can still get it in the maingame; after all, you have to get the event Celebi to unlock the Zorua in Castelia City, or an event legendary beast (like Entei) to get the Zoroark in Lostlorn Forest. Speaking of, do you want a Zorua? You can't catch them. Anywhere.