What to do as a beginner

Hi, I am a 19 year old girl trying to learn calisthenics but I cannot do a single pushup(i can sometimes do 5 knee pushups), also(I cannot dead hang for more than 5-6 seconds)

I have also tried learning the posture for frog stand, but since my core is very weak, I cant do a proper frog stand either.

Its been a month I have joined the gym and I am trying to focus on increasing my upper body strength for calisthenics, but my core is very weak. How can I start calisthenics? How long is it going to take? There is no where I can find a BEGINNER FRIENDLY calisthenics-weightlifting hybrid routine for BEGINNERS as weak as me. Can someone help?