Help achieving a specifc effect in DaVinci Resolve - glowing floating head fades in and then out Disclaimer:  I'm a total video newbie.  Until 4 days ago I had never used an NLE before or even heard the acronym.

I'm an experienced musician, and with much of the country shut down, an ex-bandmate and I have started making music together again.  We're working on a video for a rather silly cover.  The music is good, the song is silly, and we want the video to be silly too.  We are working with DaVinci Resolve, and I've spent a fair amount of time on the tutorials.  I think I have a decent command of how to use the tool, I just don't have the necessary familiarity with the many many many features to know how to do what I want...

What I want to do is to use a clip of my friend singing the lead vocal part, and then when his backup vocal part comes in, have just his head come into the scene, mouth the words "I love you", and then disappear.  Ideally it would fade in somehow and then fade out, and maybe even have a glow around it, as if it were some floating angelic being.  It could stay somewhat transparent and ghostly.

I did work through the Resolve tutorial on how to do basic effects work.  I was able to draw a shape around his head in the backing vocal clip and make the rest of the clip transparent.  Step 1 accomplished.  I'm sure I did it in a terribly inefficient way, based on the one effect that was introduced in the Resolve tutorial (delta keying, plus a mask that I drew, and then pulling wildly on controls until it did what I wanted...I'd love to know a way to just draw a shape and make everything outside of it transparent).  But in any case, step 1 done.  I have a floating head.

Step 2:  Change the position of that floating head.  I can't seem to do this though I could swear I've done it in the tutorial.  Would probably find this with enough time.

Step 3:  Give it a halo.  No idea how to do this.

Step 4: Make it fade into being and then fade out.  No idea how to do this.

It doesn't need to look perfect.  I'm not looking for complete answers.  But some guidance would be wonderful.

Thanks so much!
I found this helpful tutorial on basic compositing:


                
            

With this I was able to easily do additive compositing with a mask and I can easily adjust the position, opacity, etc.

I wanted a white glow, and as luck would have it the video was filmed in front of a white brick wall. It works great now.