Hey man, first,
TRY TO LISTEN to what many ladies have told you here!
Second: for me, my wife's first penetrative orgasm was nearly after 5 years of REALLY good and satisfactory sex! and this first time was not really intentional, it just HAPPENED! all what we were doing was trying to enjoy ourselves, and yes we tried different positions/angles/paces the main rule was "experiment while enjoying", But i'll give you three main hints that you should try:
1: If you can make her orgasm easily from clitoral stimulation, THEN >>> DO IT FIRST! then move on to penetration, as most women can reach a second orgasm much easier than the first (correct me ladies if I'm wrong on this!)
2: Use secondary stimulation with your mouth and hands: after we reached our first internal orgasm, I realized that she can really reach it much easier when other sensitive parts of her body are stimulated too (suck on her nipples, kiss her neck, deep kissing, tongue sucking, anal fingering...etc (It depends on HER, this should vary from one woman to another, you have to find out what works best for her!))
3: Try to experiment somehow with your fingers (or a dildo maybe) (if it's okay with her) trying to understand which sides and depths of her vagina is more sensitive and feels better and at which speed, from then try to apply the positions and angles that will most likely stimulate these inner areas (probability wise, many women reach inner climaxes from certain positions, you can search this on the internet)
Last, (whether these hints worked or not) and i didn't include it as a hint, because it's a kind of "cheating". Just try to stimulate her clit while penetrating! (use your hands / her hands / a vibrator) And you can definitely try the CAT position, with simple practice you can easily master it, and as far as i know, it's the magical cheat for your problem!
BUT trust the ladies up there, putting PRESSURE is a killer for sex! Just enjoy yourself as long as she is enjoying! I almost had this pressure regarding "squirting"!! I kept trying, reading, watching videos, and it started to really get frustrating for both of us, Till i was convinced (from many sources) that most women really do not squirt! (for the ladies here: this is true, right?! Please don't tell me if this isn't true!!
) and I realized, out of all the sexual pleasures, this one single thing won't make us HAPPIER unless it just happens one day unintentionally!
I hope this might help!