If the bevel does not have the desired shape or is jagged, it must first be made:
First of all, answer the question: Which grinding angle do I need?
If you have a grinding machine, you have the following options:
Manual resharpening after machine sharpening, and this again breaks down into 2 variants, depending on the machine
Hollow bevel, which is later ground further by hand (here you must adjust the bevel angle), or
immediately the correct angle for grinding machines with flat wheels
Permanent machine grinding
If you want to continue grinding by hand, you can consider a (front) micro bevel. That is, you grind a bevel angle that is slightly too small and finally apply a micro bevel with the desired cutting angle.
If you don't have a machine, your only option is to take the hard way with your roughest grindstone. Have fun!
Also, do not forget about the back side. If it is rusty, for example, you have a problem. If it is a plane iron, you may be able to grind a rear micro bevel. This is faster in the short term, but it is hard to get rid of them and you have to repeat it more often.