I’ve been using Unreal Engine for just over a month.
However, I am in a situation where I need to create an advanced effect using niagara right now.
So I ask you for help. Please help me.
Can you re-state the problem? If so, it might be a little easier to work backward. The second part of the effect is a standard emit-particles-from-a-texture sorta thing. If you look in the Unreal Example Content Niagara Advanced map, there are several demos of how to do this – you can just copy-paste them and tweak a few things. The examples are about 90% of the way to what you’re trying to do, so go ahead and copy! Never need to re-invent the wheel. 
At the beginning of the effect (the part where the numbers are solid) that shouldn’t be a single particle – it should be particles emitted from a texture which haven’t moved around yet. So, the only tricky part is working out the math of the subUVs to pick the correct section of the texture. Or better yet, just split that texture up into multiple textures to make it easier.
Good luck!