Sides of screen are not working and sometimes it does random things

I've replaced a lot of iPhone X screens, and have yet to find a way to fix any kind of touch screen issue short of installing a new screen assembly. So yes, you're going to have to replace it to fix your phone.

The good news is prices for iPhone X soft OLED screens have dropped dramatically over the last couple of years. Last time I bought one I was able to pick one up for around $15 USD, which is an amazing price for a decent quality screen. Here's the iFixit guide showing you how to do that repair.

iPhone X Screen Replacement - iFixit Repair Guide

From my own experience you'll want to take care moving the earpiece speaker assembly so you don't damage it and lose Face ID. Otherwise, follow the guide and you should be fine. If you're ordering the precut adhesive sheet for the display separately, I'd suggest ordering a couple; if you haven't had much experience with the adhesive it can be a little tricky, as it is not at all forgiving; if you get it on wrong there's no second chance, so having an extra on hand will save you having to wait to reorder before you can finish putting your phone back together.