I've only done a couple of these before so I wont be able to walk you through it.....those instructions seem to be pretty much step by step.   I would assume since the replacement property wasn't secured until 2019 that you would not need to fill out the new asset entry worksheet yet.

Did this exchange all go through a 3rd party escrow company to hold the money in between sale and purchase?  There are specific conditions (time frame) with respect to the replacement property for it to qualify as a 1031 exchange.  Merely selling a rental property and buying another one doesn't constitute a 1031 exchange.