Right Front: Cast on 49 and K1,P1 in ribbing for 8 rows. Cast on 5 sts for front facing and work as follows on 54 sts. Row 1–K 4, sl 1, K 4 * K 1, P 1 across row.
It sounds like this is going to have a turned back border of 4 stitches, the sl 1 is for the place where it turns and then you have a border of 4 stitches of st st (all the edge, the part that shows and the turn back will be st st).
Did you cast on for the right front at the beginning of the row and then work back across those new stitches first and then continue across the row? That is what it sounds like it is saying to do. If you haven’t done anything yet what I would do is to cast on the 49 and work the 8 rows of ribbing and then turn to make the next row. Right there cast on (with a knitted on cast on or perhaps a backward loop cast on) the 5 stitches and then work row 1 as given. Continue on to row 2 etc.
On the left front I would cast on 49, work the 8 rows of ribbing and then turn and work across the first row of work as follows (this will be a right side row): P1, k1 (or k1, p1 I’m not sure which. Is it ribbing or seed st? If it is ribbing do what will make it match the other side in this spot, if seed stitch either way will look okay) across to the last 4 stitches, k4. Turn to begin the next row. Cast on 5 stitches. Then you would p9 (the first 5 you work over will be the ones you just cast on), work 2 tog, k1 p1 (or k1, p1 whichever is needed to keep you in pattern) across the row.