Please don't take offense -- I'm only sharing what I see. I don't mean it to be critical of you or your skills.
The first two look like scans of Polaroid prints. The second 2 are a little better -- but have a look that I can't quite put my finger on. Somewhat soft and very low contrast in both. I like the DOF, but the color toning just doesn't work for me.
First, welcome to the forum. I don't know if you have had an opportunity to browse the various forums at FM, but those who focus on portrait work are more likely to be on the People Forum. I'm sure some cruise through here occasionally but that is really their full time home.
Like @derthax, I do not intend or mean to be rude or unkind but I think it would be more beneficial if you would study posts and comments on that forum, and if you want, also post images here for comment.
As to your posts, and I don't scan images so I am just guessing, but the file names and Exif data suggest these are scans. I have not shot film in a long time, but #1 looks to be the only one close to being properly exposed.
I pulled #3 into Capture NX2 and the color balance is way out of whack and there are artifacts from the scan (looks like paper surface) and noise all over - imo it is beyond salvaging.
I may be completely wrong (won't be the first time) - I suggest practice, visiting the People Forum, and if you must scan, find out how to scan slides or negatives, not what seem to be prints.
Welcome. The images have a beautiful model that appears suffering from shyness.
Then there is the pervasive blue tinge and light issues. As to the composition only
#1 and #2 appear to somewhat capture my interest. The DOF on #3 and #4 is at
best intriguing. I hope my comments do not demotivate you.