CompactLogix units are really powerful and easy to program. But I'm sure the other guys will agree: you will find in dealing with AB products there's a fee for everything. Licenses for RSLogix 5000 software are not cheap ($1000+), nor is PanelBuilder32 ($800+).
Check out this url: https://theautomationblog.com/what-software-do-i-need-to-program-compactlogix-or-controllogix/
When I started working with our Logix units, we bought a USB dongle that allowed me to use a single software license on any computer the dongle was connected to. This allowed me to set up a test rig in my office, as well as do onsite programming in the field. The cost was around $150 for this dongle.
They also have cloud-based licensing which allows you to check in/out a license from multiple locations via the internet. Helpful if you're doing work in multiple remote locations. Not sure the pricing on that.
I just logged into Rockwell to see if they offer any free Studio5000 downloads, but unfortunately I can't find any.
The cheapest option for someone learning the ropes is to borrow a friend's laptop which already has the software installed.
You just need a battery and the software. Any program will do in a test / learning rig. There are a number of sample programs bundled with RS Logix, lots to play about with.