Welcome to 2CarPros.
Well my first though is that the battery is extremely low and you can either put a battery charger on it or use a battery jump pack and see if it will start. As it sat for a week and is now that discharged I will further post that you need to have the battery and charging system tested to see if it is charging properly and the battery is actually good, once you do get it started.
Next the clicking and losing power are not good signs. Those could be low oil related. As such you should check the oil level before you attempt to start it. Ideally it should be on level ground, then take a paper towel or rag, pull the dip stick out. Wipe it off, then reinstall it. Now pull it and read the level. If it is low simply add some to bring it up to the full mark. If it is dark brown/black it needs to be changed once you get it started and run a bit.
If you can charge or have it jump started with a pack, and the oil level is okay you can make a recording of the sound and post it on this site and we can try to identify what the problem is.
Thursday, May 31st, 2018 AT 7:24 PM