I found out that I can tick the box that says "Resize", however when I run the game, it resizes, but not the elements, the map panel and the stats panel are all stuck at the 1280 x 720 res I set, How do I also make the elements resizeable?
You need to set anchors for your skin elements.

You can think of anchor points as percentages of the window (internal) size, so an anchor of 50,0 means 50% X, 0% Y, or middle top. 0,0 is obviously top left, and 100,100 is bottom right.

Each control can have two anchor points: one for its top left corner, one for the bottom right. The corners of the control stay in the same position relative to the anchor. So if you have anchors of 0,0 and 100,100, the top left of the control stays in the same position relative to the top left of the window, and the bottom right of the control stays in the same place relative to the bottom right oft he window; in other words, it'll grow with the window.

In most cases, but not always, you'll want to anchor to either a corner or a side. The most common anchor points are already available in the dropdown selections, but you can set custom anchors too.