How to simulate intercourse?

Strip down to your pants and bra then slowly stroke your pants over your vagina. Once your wet, stroke faster and also stroke your thighs. When you feel sexy and are really wet, slip a finger inside your pants through one of your leg holes. Stick the finger into your vagina then out again, keep doing that faster and faster and you should get a pleasurable feeling.

Can I stick my finger in my rectum to get the same pleasure?

get some sort of tube shaped object, then make yourself turned on or turned on in whatever way feels best, once you feel wet and like your ready, strip down and stick that object into your vagina, slowly at first, but then much faster as it continues, if you feel like you aren't turned on enough, then watch pornography or some other arousing content, this should increase pleasure.