You need to enter you functions correctly. Also, I forgot some parenthesis around the second example. g[1] took precedence over the composition.
In[1]:= f[x_] := x^2 + 2
g[x_] := 4 x - 5
In[2]:= f@*g@1
Out[2]= 3
In[3]:= (f@*g)[1]
Out[3]= 3
Regards,
Neil