i m not a pro write and i dont know how to explain things well
but i do know how to play
Your guitar progress.
Every guitarist face this.
But strumming is all about Timing.
To start with stumming
you should practise four downstrum first
with count like 1234 1234
any chord you like for ex Am chord
D D D D
next step would be
DUDUDUDU
it is similar to DDDD but here you just have
to strum in upward direction too.
timing in both is similar
so first practice these two basic patterns
and you can refer to
learn basic patterns with strumming videos and good theory explanation