Conversion to Fast Basic can be tedious. I use LIST to save the program in ATASCII format on an emulator. Use AtariUtil to extract it as text file so it gets converted to standard ASCII. Use a program like PSPAD or MS VSCode on PC, Mac, or Linux OS. That is so I have something I can do find and replace functions. PSPAD also has column selection so to make it easier to remove line numbers.
What you first need to do is find all the GOTOs, Gosubs, IF-THEN [Line number] statements and change to PROC-ENDPROC, Do Loop, Repeat Until, While Wend. You could be doing a lot of copying and pasting.
Once you start converting the program in Fast Basic forum, it actually becomes easier to follow.
A few weeks ago, I copied a few old Compute! Magazine type in games to ASCII. Had not got around to converting them yet. If anyone is interested in assisting me with porting them, I will post them on GITHUB.
I always say if anyone makes new programming languages for Atari and related platforms, it is helpful if we have many public examples. I just about ported every Turbobasic program I had in my posession, and now moving to magazine programs that are already public domain.