Rejoining yarn to last ##stitches left on the needle

Hi there
New to this wonderful knitting forum.
I am working on easy 2needle child mittens.
Pattern found at
I have juust finished off the thumb and am now ready to start TOP
Pattern states: with wrong side facing, rejoin yarn to last 18 stitches left on the needle, purl 18
Continue on 36 sts, work 6 rows

Question: the wrong side is the purl side, however the needle is aroundthe wtong way, ie can’t take stitches off needle after stitch… also do I join the yarn soo that there is 18 stitches on either side, but do I knit to the left or the right?
Any advice would be most appreciated.

Welcome to KH!

The point of the needle should be facing toward the thumb. If everything else looks ok, you can slip the sts off onto a dpn or circular needle and then reverse your straight needle so that you can purl across these 15sts.

If you followed the pattern, the straight needle will be in the correct orientation however. You knit across an earlier row, turned at the end, purled across 26sts and then turned after the thumb sts. That leaves the remaining unworked sts on the left needle and ready to be worked after the thumb is completed.
You should have 30sts at this point, 15 on each side of the thumb.