Your audio interface may well have some kind of indicator to let you know whether you are clipping on the way through it. As long as you
aren't, you should be fine in your DAW (as even an unexpectedly low DI guitar signal in the DAW can usually be gained up just fine if necessary).
Another thing you can do is put a metering plugin both before and after AmpliTube in your DAW. Then you can see just what your levels are both going into and coming out of AmpliTube -- and, if your metering plugin lets you gain things up or down (which many do) you can adjust things there.
Although I don't think IKM officially recommends a reference level for going into AmpliTube, many plugin makers recommend levels hovering around -18 dBFS, so I tend to set my metering/gain plugin in front of Amplitube to keep things around there (just in case!). I'll then adjust the Input control within AmpliTube if necessary to ensure the AmpliTube's input meter isn't peaking higher than in the "yellow". I believe the official manual actually suggests:
"Set your audio device’s input gain so that AmpliTube’s INPUT LEVEL meter is starting to go into the red, then back off just a touch." Very technical, I know
but, well, OK then!
The stock AmpliTube presets tend to leave the input control at +/-0, so I leave my own presets that way, too, and then gain the DI signal up or down before and/or within AmpliTube as appropriate.
Then, I find that output from AmpliTube can be pretty high, so I also have a metering/gain plugin after AmpliTube, and I'll dial back the output level within Amplitube until my metering plugin is again showing around -18 dBFS (so that it's likely to be at a happy level for any other subsequent, downstream plugins). Probably I should always use the mixer controls in the Cab Room portion of AmpliTube to adjust output, but I generally just grab the output dial and roll it back. It is quite possible with some amp model configurations to roll the output dial
all the way back but
still have output levels that are on the hot side
so that's when I go into the mixer controls in the Cab Room.