Two lymph nodes removed and both negative

You can get lymphedema with only one node removed but I would not restrict use of that arm.  When you fail to use the arm and it weakens you can be at higher risk for LE because of those times when you have to use the arm, you will be less prepared.  It sounds like the kind of carrying you are referring to is not new, and therefore should not cause new strain.  The most important thing to do is listen to your body.  If it feels different, sore or aching, stop with the lifting.  If you were considering sustained lifting, like with weight training, I would suggest seeing a lymphedema therapist to discuss if you should wear a sleeve for such occasions, but for things like carrying groceries and suitcases I think you should just keep doing what you've been doing.  Just listen to your body.