Phone shut off while I was using it just reads 0% now wont charge

The battery can be replaced via this guide: iPhone 8电池更换

However, the bootloop may be more of a tricky issue. If you have your data backed up, it might be a good idea to factory reset your iphone via the DFU mode and itunes on your laptop/PC. However, be warned, this will wipe all data off your iphone. It doesn’t always work, but I have been able to restore bootlooping iphones via this method before. Here’s the link, in case you’re interested.