Welcome to the hobby of wildlife photography. You can get some good pics with that camera. That's the level of gear that I started with. Unfortunately, big glass is expensive, often more than the camera. 55mm is just going to be frustrating for you. That is a good lens for portraits, street photography and such, but birds are small and generally won't let you get close enough for that to work for you. The ideal would be the Canon 100-400mm. Unfortunately, those are way out of your budget, though something to save up for in the future while they are still available.
There are still some good compromises to look at though. Tamron makes or made an 18-400mm with the EF mount that I can see ranging from $400-$600 retail used. The Sigma 150-600mm is quite good and I often use it when working with shore birds and the like that are often at long distance, but even used it is probably $500-$600. Also, I see the used Canon 100-400mm as low as $200. But that would be an older model and make sure you try it out on your camera body before buying as at that price it is probably seen a lot of use and might have some issues, or at least buy online from a highly reputable merchant who will allow returns if it doesn't work out for you. I've successfully used B&H and Adorama (both out of New York city) and found both to be very reliable and with a huge inventory.
https://www.adorama.com/us1527221.html
Also keep an eye on your local craigslist if you are comfortable with meeting up with strangers to exchange money for product. My experience there though is that usually everything listed there is vastly overpriced. Doesn't hurt to check out pawn shops or see if local auction listings look like they might have some camera gear of interest to you, just remember, no returns at either of those. If there are any small local photography shops they might even have some used equipment and be willing to dicker over prices.
There are a few ways to get started with what you have. Hummingbird feeders provide a real opportunity to get really close and provide colorful subjects. It requires patience and spending some time slowly working your way closer as the birds get used to you and occasionally one will put on a display for the "bird" it sees reflected in the lens. Regular bird feeders can also provide the same type of opportunities, though even more willingness to slowly work closer over a long time as the birds get used to you.
Great hobby with endless opportunity for continues learning and always an excuse for getting outside and enjoying nature or for an new adventure.
