If your charger is QC2 or QC3 charger, then negotiations will occur over DP/DM lines.
If not, the supplied voltage will be +5VSAFE, and the capability of charger will be advertised on Type-C end. The CC pins are not present in the Type-A end of cable, but they do present in Type-C end of charging cable. If the specific cable came with specific charger, it is likely that the pull-up inside the Type-C overmold reflects the charger capability, meaning that the pull-ups on CC line can be 56k (500 mA), 22k (1500 mA), or 10k (3000mA max). The device being charged likely reads the pull-up value and takes the current accordingly.
For more accurate answer it would be advisable to identify exactly what kind of "a charger" do you have, with its specifications.