OH, boy, as chance to get on soapbox.........Welcome to twinsanity!!
When are you ready for twins? I really cannot add much to above comments. DO NOT DO A SCALE TWIN FIRST!! Been there, done that...don't do that.
Let me ask this. Do you ALWAYS fly using the rudder in coordinated turns? If not, learn NOW. DO NOT fly twins without this skill, you cannot learn with an engine out.
The above recommendations are great, including the twin fuse conversion, as they are very forgiving, but not the same as a single engine plane. ALWAYS use a partner to do the vertical test before each and every flight. On a single, you might skip this and get by with a straight ahead dead stick landing. On a twin, lose an engine on takeoff and you loose the plane to a snap roll...NOW!
Due to higher wing loading, they "feel" heavier, that is they are harder to roll and get stopped, harder to loop and come out, and land a bit faster than you are normally accustomed to.
Can you fly a twin on a single engine? Depends on the plane. Personally, the Cedar Hobbies will take off and fly on one single engine, roll and carefull loop. ( Note, do not try this, I am crazy!) Try to fly a P-38 on a single engine, and I have owned five, including two now, and you will snap roll and crash. The VQ P-61, I have flown the prototype and lost an engine and other than a heart attack, it was easy to control to a landing. I just this weekend started to fly my VQ P-61, but kept both engines running..(Thank GOD)
How many planes have you flown and are any of them heavier wing loading? I am not an expert on single engine warbirds that have high wing loading, but most do and will snap into the ground if flown too slow on approach.
Look at above comments for ARF's or kits and you will find it not as scary as one might think, but go slow and you will enjoy this more and be the talk or envy, whichever you prefer, of your flying field.
Good Luck and welcome aboard.
Twinman