FORTRAN first, but then BASIC
FORTRAN was the first programming language I learnt (at university in 1970). It was Waterloo FORTAN (WATFOR), a limited version for new students, that stopped after 1000 lines of execution so infinite loops didn't bring the whole system to a halt. We wrote the programs on forms that were punched by the operators and the results returned by a print-out wrapped around the punch cards. If we needed to resubmit with corrections, we could punch our own cards.
My first job involved an in-house system called PROCALC, basically FORTRAN with tweaks that ran live - but could be used to submit FORTRAN programs to the batch system. I learnt BASIC in 1976 when I needed to use a Varian micro for a project I was working on - I was handed the instruction book and let loose. That computer, like the previous one, interfaced via a teletype but also had a screen which could be used for the results. Essential for my project as I was working on a system for pattern recognition - limited capability in 32kB of RAM, but it was a start.
My favourite BASIC was the BBC variant (on my Electron - now back in its original box in my attic) - the ability to insert assembler directly into teh program gave it a lot of additional power; the assembler was compiled on the first pass, even though the rest of the program was interpreted. Allowed me to write screen grab routines to some weird printers, and to modify games (typed in from magazines) to access a co-pro. Who remembers the "tube" - allowed the program to run on one 6502 while the graphic processing ran on another. I had a maze game that, in the magazine had wire-frame walls, but ran with solid, shaded walls on my Electron, and with smoother motion. Rubbish compared to today's systems but not bad for the 80's.