As a new tax preparer and to Lacerte, does Form 1040 include Form 540 when e-filing?

The Lacerte diagnostics will usually tell you what, if anything, you need to manually attach to the returns.

Generally W-2's and 1099's are not needed to be attached, and definitely not 1095's.

For the 540, the whole federal return will/should automatically go with it.

The only thing I regularly attach is 1099-B brokerage sale details so that I can just enter totals into Screen 17.

Whatever you do need to attach, you do that on screen 4.4 and select which returns (federal and each state) you want to attach it to.  Keep in mind that your attachment usually won't print in your client, gov't  and preparer copies of the returns; so don't freak out if you don't see them.

The F 540 "includes" the F 1040 (not the other way around...).

Lacerte is pretty darned good at including what's necessary.

You *do* have to specifically efile the CA return - there's a box to check to send CA at the same time as you efile the Federal.