Am I able to partition my internal SSD safely without loss of data?
I am wondering if it's safely guaranteed 


No.  Period.

Nothing is "safely guaranteed." Generally speaking (as at the time of this answer your question is lacking in detail), you can (re)partition without corruption of your data.  That's not to say the process is infallible.  Problems happen, mistakes can be made.  This is why is so important to have a backup of your data.