Recommended px size for ur desings?

@Shadow1235DCB A4 is a print standard, not a digital standard. Honestly, I would create a portfolio website that is responsive as this approach would be ideal for presenting your designs for a Visual Communication degree application, as it natively handles viewing across various devices scren sizes like phones and PCs. It's been awhile since I last applied for art school and if it requires a specific fixed-size digital file (like a PDF or images to upload) as part of the initial application or portfolio submission I would shoot for 1920 x 1080 for 16:9 aspect ratio, because this would be large enough to look crisp on most screens (including most high-resolution monitors) without being so massive that it causes slow loading times or file size issues for the submission portal. 1920px is the standard Full HD (1080p) width. Since the work will only be viewed on a screen (not printed), a higher resolution isn't necessary and only increases the file size unnecessarily. Unless, you are saving as a PDF, then I might make it at 300ppi, but your file sizes will be quite large to download! 

But double check the school's requirements they may specifically mandates a print-based size like A4, letter size or a high-dpi requirement.