Joel

There are a few ways to figure out what device you have. The S-pen or stylus is a way to tell if you have a Samsung Galaxy Note. If you know you have a Samsung Galaxy Note then size is a factor. The Samsung Galaxy Note 8.0 has dimensions of 8.30in x 5.35in.

There are a few different factors that could be involved. First I would check to see if your device is charged. Plug in your device and see if it responds. If it does then you either need to charge your device or the battery is not holding a charge, meaning you need to replace the battery. If this is not the case then a faulty power button is another possibility. There are replacement guides for all these cases.

Yes the screen is replaceable. There are different ways to replace the screen. You can check out the screen replacement guide for more information.

The speakers are probably not working properly. Check out the the speaker replacement guide for more information.

The battery is replaceable. Check out the battery replacement guide