Help with sleeves

I’m trying to learn knitting by myself. The top I’m working on needs some stitches cast on for the sleeves. Just about 10 will be enough for cap sleeves. I don’t know how to add cast on stitches to accomplish this. Can anyone help?
Please and Thank you

What pattern is it? Where do you cast on, at the beg or end of a row?

If it’s at the edge, you can use a knitted or cable cast on, using the edge st in place of the slip knot. I’d CO 5 sts at the beg of 4 rows to get you 10 on each side’ that way they’re more gradual.

But if it another type of top, we need more information.

The directions say to cast on 10 stitches at the beginning of the next 2 rows. I’m not sure how to do this the only cast on I know is the slingshot method

Look at the CO videos, and use either knit or cable. Instead of starting with a slipknot, you pretend you already have sts, and insert the right needle into the first one on the left needle for knitted) or between the first two for the Cable. Then wrap your yarn around and bring it through and put the new st on the left needle.