Glad to see that others have pointed out the potential errors in using an enlarger if you don't select
the even part of the field. If you don't have a good transmission densitometer, then contact print
onto a hard grade paper to exaggerate any issues with the film itself. Try to expose the film somewhere around an even middle gray or gray card value. There are any number of ways to dev
film very evenly - tray, drum, brush dev, nitrogen burst, whatever - the most important thing is practice, consistency, then learning the finer points of each technique.