Before you replace the card itself I would make sure you're running current drivers. And/or do a network reset. In windows 10 you can do that right from the Network settings pane, there's an option towards the bottom. That way you can rule out some weird software issue as a cause. But if drivers are up to date, and you're not experiencing issues with other devices in the same location, then I would say it's worth your time to give an upgrade a go.
You've got a couple options. If you want to install an internal card, replacing the one you have now, you will probably need to open the machine and see what sort of card is in there now. There are a couple of different form factors and the best way to confirm what you have right now is to lay eyes on it. I believe this machine, and most modern laptops without soldered on WiFi, use an m.2 slot, but since the A315 has multiple variants, it's hard to know for sure exactly which one your machine has. Once you know what slot you have for WiFi, you would just need to find a card that matches, and assumedly has better specs.
Your other option, is to get a USB WiFi dongle. You can probably find one of those in a physical store, They are availible in a host of qualities, speeds, sizes, and are much more universally compatible. Plus they are easier to install. The downside is that consume a USB port. And they can be pretty chunky depending on which one you pick, so they may affect the portability of your machine.