The pattern is asking me to decrease both ends of the 14 following alternate rows, Do I need to to k1 sl1 psso at the start and k2tog at the end. And purl the next row 14 times

Do you mean sl1 k1 psso (skp)? That would be a left leaning decrease.

Yes sorry. but is the next row a purl row. and so I repeat this decreasing row 14 times