Cisco Console Rollover Cable – RJ45 M/M Putty connection

You can erase the startup-config and reload to get the factory configuration.

I think you mean Layer-3, not Level 3, and it is a Layer-3 switch.

A best practice for security is to disable the HTTP server and HTTP secure-server in Cisco devices, but you can enable it with the ip http server command. You will need to have a configured IP address on the switch which you can reach for the web interface to work.

Without a complete network design, we can't begin to guess how you have it connected or your needs, and we would just be guessing on a proper configuration.

Note:

This is all very simple stuff for a switch, and I would strongly recommend you get someone who knows how to do this to configure it for you. It is not a simple thing like a home router, and it sounds like you don't have a firewall protecting it, which seems a very foolish idea.

The default serial settings in Putty are not adapted to connect to a Cisco device.

Try those settings : (I.E. change Flow control to "None")

Edit in response to the last sentence of the original post.

You should not be afraid to appear as "dumb". We all did mistake, often much more serious than this one. Only people that do nothing never do mistakes.

I would not trust at all someone that claims he never made error. It's a liar.

But I do trust people that do mistakes, endorse them, and do their best to correct them.

Errors are one of the best way to learn... (see you will learn how to connect to a Cisco device trough serial console, which is still a must-have skill in network engineering).