If you hold a PPL with CPL TK and FI rating then you will be able to be paid to instruct for the EASA PPL. If you haven't demonstrated CPL TK, then it's just instructing for the LAPL.
Cost:
Not sure if you have a PPL:
PPL 45hrs = 7500
155hrs hour build x 125 ph 19375
FI 7000
To teach LAPL
To teach PPL
add CPL exams 2500
I mention cost because some don’t and it’s a pretty vital part of the flying equation unfortunately. From zero to a PPL FI is over 30K these days, quite an outlay. For very small or no income at all, at your age of course it may lead to much better paid aviation jobs.