In my opinion and based on considerable experience, I believe your first firearm should be a S&W .22 LR revolver. Easy to learn basic gun safety. Easy to learn advanced combat techniques. Most are competition worthy, or close to it, right out of the box. Excellent triggers. Excellently built. Easy to maintain. Cheap to shoot. Good for damn near everything from plinking, to target shooting to hunting to self defense. A wide array of affordable ammo. Easy access to accessories. I could go on and on.
I'd look for a model 17 K-22 masterpiece or something similar.