The trap with kotlin is that most teaching aids target those moving from java, and on that basis continually assume a strong knowledge of java. It can be very frustrating to have concept explained in terms of java, requiring the reader to learn how the feature works in java before the instructions for kotlin make sense.
There are now online courses that teach kotlin without any prior knowledge, but these tend to be very basic, as no programming knowledge at all is assumed. The biggest ‘missing link’ is the lack of exapnations of kotlin advanced features for programmers coming from any language other than java.
We have a project that we are planning to migrate sections, or perhaps even the entire project from python to kotlin. and are finding documentation a barrier. The support material for learning kotlin is at its worst for those who have already learnt advanced programming, but do not specifically know java.
Realistically, if you do not know how to program, sadly currently the best advice is probably to learn java first. Next choice is just learn as you go with kotlin but be aware there is simple less learn to code material and much material for advanced concepts assumes java knowledge. Becoming proficient in a language other than currently may simply create significant frustration when bringing the skills learnt to kotlin, only to find the kotlin documentation specifically knowledge of each step in java a prerequisite for the kotlin documentation.
As kotlin matures, and a wide range of support emerges, the contradiction of a language that makes java redundant requiring programmers to learn java will fade to nothing.