My phone wont boot or show any signs of charging

If you know for sure that the phone was working prior:

After a battery has been flat for an extended period of time, it may or may not come back to life.

Try and charge it using a known good cable and charger for an extended period of time. 3-4 hours or overnight. This may wake it up, but may also cause it to inflate since it has been flat and idle for so long.

If extended charging does not solve it, you need to try a new battery.

If you're not sure the phone was working properly before you lost it, it could be the above, or the screen is broken/dead, or the board has failed from component failure or external damage like drop or liquid spill.