Can all women "squirt " when having intercourse? & if so how?

Yes. Orgasm can cause strong contractions of the muscles in the vagina and pelvis. This can cause "squirting" of fluids from the vagina, or even urine. It is not uncommon, and generally not worrisome.
No. By squirt i will assume you are referring to exuberant secretions from the sex glands and not the bladder. Most women will only secrete avereage amounts of lubrication with sexual excitement while a smaller number have discribed a large excretion or "squirt". The pupose of these glands is lubrication for intercourse.