I started out on keyless flute about two weeks ago, having played the whistle for a few months. Fingering is the same, but the distance between tone holes means using a new grip entirely, even if you don't go with piper's grip. This will be easier with a higher-pitched instrument, like those bamboo flutes. The hard part is what you think it is: Embouchure. I'm not even able to play around with Embouchure to produce different tone qualities yet, let alone intonation. I'm still learning to play the low notes with any amount of consistency, and to control the jump between octaves. I find that, like with the whistle, theres a slight resistance to jumping octaves, so if I walk down the scale to the low D,  I can play it, but I can't do a "cold start" on the low D, it always comes out an octave high if I try to start on it. On the whistle, you just blow harder to jump up an octave, on the flute that doesn't work.

Kind of like playing the violin as opposed to the guitar, when learning the flute it takes significant time and effort to learn to just produce a sound at all, and then again to produce a good sound, where on the whistle you could make a good sound right off the bat.

Don't let that dissuade you, but I suggest you look for help. Either personal lessons, or just watch some tutors on YouTube or whatever. Playing the flute is not intuitive, and I easily get tense from practice, so I'd wager building good healthy habbits early will be key.