Help loose caston,an sts

New to group. Im a loose knitter ive been told. But my problem is caston sts are loose n baggy , the 1sts /last st of each row is always so loose , but sts in btween are all same, cast off are gud.
Not sure how 2 add pics
Thanks in advance

Welcome to the forum!
What kind of cast on did you use? Quite often the edge sts seem loose and floppy but the extra yarn gets taken up by adjoining sts and the edge evens out.
If the entire cast on row is loose, you might try casting on with a size smaller needle. If it’s just the 2 edge sts, there are ways of slipping the first stitch of each row to neaten the edges. You might have to add an extra 2 sts to whatever you’re making to compensate for these slipped sts. This works well when the edges are exposed as in a scarf but aren’t really necessary if the edges will become part of a seam.

Here’s a photo that shows you where to start posting photos beginning in the Reply box.
Screenshot (3)_LI
From there, follow the prompts to choose and upload a file.

I always treat the first stitch of the row with care. I pinch it between my finger and thumb so that extra yarn is less likely to be pulled into I when making the new stitchnuntonit. I am also more careful when dropping that first stitch off the needle and kind of withdraw the left needle from it rather than than dragging or pulling at the stitch.
Sounds like a lot of effort but it really isn’t, just a little more careful not to distort the stitch or put it under pressure.

I frequently use a larger needle for cast on because if I’m making a sweater I want it stretchy, it looks a but loopy to begin with but evens up. So I don’t consider it a bad thing for the cast on to be a bit loose.

Like salmonmac said you can change to a different size needle for cast on if it makes things neater and more even for you.