In[]:=
forcePickAtLeastOneSym=True;pwdLen=8;alph=Alphabet[];alphUP=ToUpperCase[Alphabet[]];nums=Range[0,9];syms={"!","+","_","$","@","-","\\","/"};list=Catenate[{alph,nums,alphUP,syms}];word=RandomChoice[list,pwdLen];If[forcePickAtLeastOneSym,symbol=RandomChoice[syms],symbol=""];StringJoin[Map[ToString[#]&,word],symbol]
Out[]=
5wa8NZgb/
Out[]=