While in the Applied Economics Program, students should avail themselves of the opportunity to become proficient in one of the widely used Econometric software packages — Stata, EViews, or SAS. The freeware R also enjoys popularity, particularly among statisticians.
Note, however, that Statistics instructors tend to rely on Excel. They will allow you to turn in your work done with any package, but you cannot expect software support from your instructor except with Excel.
In both Core and Elective Econometrics courses, and in the more econometric software intensive electives, the software package in use correlates with the discipline of the instructor: Microeconomists tend to prefer Stata, while Macroeconomists tend to prefer EViews. Here, too, instructors will generally allow you to turn in your work done with any package, but you cannot expect software inormation from the instructor, except with his or her software of choice. You might choose a software package along the same disciplinary lines, or go with one available at your place of employment. If you are completely free to choose, note that EViews, with a graphical user interface, is easiest to learn, at least at first. Stata is most common for economics researchers. Do consider R, which is widespread among statisticians.
The Applied Economics Program has 68 Stata, EViews, R, and SAS equipped terminals available — 50 for teaching purposes, and 18 for student use. You should seriously consider purchasing a package for personal use, especially if you do not have access to your software of choice at work. All these are offered without charge to JHU students and faculty, or in relatively inexpensive student editions. Please look here.
SAS is available without charge here.
Other software is available without charge here.
Consider searching for on-line learning aids. Stata, e.g., is here.