Do it like so
all: program1 program2
program1: program1.c
gcc -o program1 program1.c
program2: program2.c
gcc -o program2 program2.c
You said you don’t want advanced stuff, but you could also shorten it like this based on some default rules.
all: program1 program2
program1: program1.c
program2: program2.c