Should I learn mobile development after Web development?

I am currently in highschool and I am close to finishing a udemy web development course (frontend and django backend) I know python and basic c . But when i created my first few websites it occurred to me it will be more efficient to put my ideas into apps ?

Should I now after web development start with apps ?

And if I do what language and frameworks should I use based on what I already know ( I want to build native apps ios or android or both Not phonegap etc apps)

I have not dived into the topic of RESTful API but is there a way to use the same database for a django website and a native mobile app coded with another language ? Again, not ports like phonegap

Sorry, I know this is alot of questions that actually should be one . Thanks in advance