Pattern help

[Jacparrish]

I’m making this free pattern with the link here.
https://www.girliescrochet.com/granny-tote-bag.html I’ve made the first row but I don’t know how to finish the first row and continue to the second. I’m also confused if this pattern should be worked in the round or if I make the front and back separately and then combine them at the end.  

[Granny Square]

Welcome to the 'ville!  You are asking a question about a transaction that stumps a lot of folks, I think because a lot of patterns (like yours) don't explain 'what is going on' very well.  You are working in the round, from the bottom of the bag up, but probably not in a way you have before.

You made a chain, and then stitches across the chain, ending at the word 'across' - OK so far.

The next words are 'on the other side' - what it means is 'on the other side of the chain'.  there are several ways to work into a chain*, and none of them use ALL the loops, there's at least 1 left over.  You will be making a long skinny oval, up 1 side of the chain and down the other--you are making the bottom of an envelope all in 1 piece, and the chain is the 'fold'.

*for ovals, I do not recommend making your initial pass using the 'back bump', because it pulls the chain tight.  Rather, with the back bump facing away from you, and the chain-looking part facing you, work around either (1) into the topmost loop, or (2) around the topmost loop + the back loop, leaving the bottom loop free.  On the second pass, work around the 1 or 2 loops that are left over.