I had to giggle, and "tone, tighten, and build..."
If I'm doing a show / contest, I STOP training 12 days out to allow my legs to split and so on.
It takes weeks, months, and years for some of the adaptations. That being said..here's some tips.
Lots of how you look is water balance. Get dry. It'll make you look thinner.
Might as well circuit train on the weights. You won't gain much size in three weeks.
Do interval training and you'll drop some fat, and some water.
Otherwise, stay the road, and check back in 6 months.
Honestly, in a month, unless you're really good, it's hard to make lots of changes. You can drop a percent in fat, maybe, with a strict diet. You can drop off bloat. You're not gonna' get buff in a month, though.
You have to learn patience, and discipline. It's how the game works.