The best lens for your situation depends upon the sport(s) you wish to photograph and where you will be located. For indoor sports with that camera, you will need a wide aperture (low minimum f number) lens which will transmit as much light as possible to your camera.
Lower costs lenses that will work if you are close to the action include Canon's EF 85 f1.8 and a 50 f1.8 (or even better a 50 f1.4) from Canon or others. But if you are further away from the action, you will need a lens with greater focal length and that gets expensive quickly even used.
I just started to process photos from a basketball game I shot tonight and I shoot from the end court just outside the lines. For basketball, I use three 1DX series bodies with EF 24-70 f2.8, EF 70-200 f2.8, and EF 300 f2.8 lenses depending upon where the action is on the court. None of these are inexpensive but the action I captured with the EF 24-70 f2.8 (near the goal work) could be captured with a 50 f1.8 on your camera and an 85 f1.8 would get a little more reach.
For many years, I used an EF 85 f1.8 for poorly illuminated venues.
So let us know the sports and what sort of access you have near the playing area and that will help members provide guidance for what will serve you best.
These are a few images I quickly grabbed from tonight before I do the main processing tomorrow, the first was captured with an EF 24-70 f2.8 on a 1DX II body, the second with an EF 70-200 f2.8 on a 1DX III body, and the last with an EF 300 f2.8 on a 1DX III body. The further away from the action you are, the more expensive the lens to capture it well.
Rodger
Thank you and wrestling is not a sport I have shot often but it is a little less demanding of equipment than some sports. A lot of wrestling photos can be successfully captured at 1/500 which is a shutter speed that would create motion blur in almost every image in basketball. Generally you can get pretty close access so the EF 50 f 1.8 would work well and is inexpensive, the EF 85 f 1.8 would also work well for you.
These were shot with EF 135 and EF 200 f2 lenses on 1DX and 1DX Mark II bodies @ 1/640 and those are what I had with me from shooting another event; shooting these matches wasn't planned or I would have brought shorter glass and gotten closer. It worked out OK because the match official was retiring after this event and he was happy to have some nice action photos of his last matches.
Rodger
