I guess for me the main one I didn't know was that you need to put up quite a few sats and open a bunch of channels. You can swap out & reuse those onchain TX to create new channels.

Not enough large channels might cause too many failed payments which can be frustrating.

You likely won't gain any sats by opening channels in this higher fee environment, so you'd be doing it for learning/experience or because you want to help the lightning network grow.

Also you need to be comfortable keeping funds online in a hot wallet.

Finally know that LND (umbrel) use AEZEED seeds! Not BIP39