Hello,

i want to play Pokemon on my laptop. Do you have any recommandations for a safe and running emulator ?

For 1st, 2nd (GB) and 3rd (GBA) generation games, you can use the following:
Visual Boy Advance:
http://www.emulator-zone.com/doc.php/gba/vboyadvance.html

For 4th and 5th (NDS) generation games, try the following:
DeSmuME:
http://desmume.org/

I do not know emulators beyond that, which can be used for 6th and 7th (3DS/N3DS) or 8th (Switch). Maybe somebody else can provide further insights regarding those..