I want to know if there are exercises of RISC assembly programming language to do?I understand the assembly language but there is nothing to implement in assembly.So I want to know if there are some resources to implement programs in assembly?
Yes, it's one thing to understand each instructions from the manual and it's another thing to combine them to implement (efficiently) this or this functionality.
One thing I've done often is to compile some small functions (and indeed things like strlen() and friends are a good start) and then to study the resulting assembly, understanding the interesting tricks and optimizations, exploring which instructions can be used for what.
After a short while you will begin to think like "hey, why is this done like this? It will be simpler/shorter/more efficient to do it this other way". You can then begin to try your new idea and you have now a very concrete objective for some code to write.