Unfortunately, I have found that InTune training is hard to come by. When we implemented InTune (when I say, we I actually mean "I") I grabbed a book from Amazon about it, and then dove straight in. The book I purchased:
The book was sufficient to give me a start, and coupled with Microsoft Docs we were able to get fully up and running in InTune within a month. It's really not that hard until you start wanting to push out user certificates which requires an NDES server, but the documentation for setting up NDES with your CA is well documented, and I didn't run into any major hurdles, minus a tricky situation on how you name your NDES CA template meant for InTune. Tip: spaces don't matter when calling the name of a certificate template.
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Good luck! But I recommend just grabbing some spare phones you might have, setting them up through Apple DEP if you have it. If it's just Androids it's even easier as you really just install Company Portal, register the phone, and call it a day.
Feel free to reach out if you have any questions!