I have some information on Iring's excellent Post.
(1) Yes - absolutely - the HIS CLIENT comes with a piece of software (the 3270 client), that you an use to log into 3270 sessions.
HOWEVEVER
(a) to my knowledge, a 3270 session from the 3270 client can only be established if HIS or SNA sever has a PU2 connection to a VTAM (SNA) node, and the VTAM node has defined within it LU 2 definitions that go to a mainframe application that supports LU2 connections (sub area networking).
(b) The 3270 client is LU2. I took the nature of your question on "practice" to indicate that you wanted to do Application to Application testing (APPC/CPIC/LU 6.2.) There is no support for Windows to Windows LU 2 that I know of.
(c) In theory, HIS supports WINDOWS to WINDOWS LU 6.2 connections, but, again to my knowledge, only with an intermediate VTAM (SNA mainframe) node. I've thought about trying to use DLS without an intermediate SNA node, but I somehow doubt that that would work.