how can I resolve "502 Bad Gateway nginx/1.14.0 (Ubuntu)" ?

Hi. I’m the new one want to use DigitalOcean and I must admit I don’t have many knowledge of server

I wanted to make blog with Ghost… but even I couldn’t see basic theme of Ghost

when I write on domain of web, I have got this error message

502 Bad Gateway
nginx/1.14.0 (Ubuntu)

I’m gonna let you know my progress

I created droplet and my ssh key. and I spent hard time because, permission of my public key was denied. but finally I solved this problem. and console requested me my blog url. so I wrote my custom domain that connected my droplet ip address. and I requested my ip address website. but I have got error.

I found some information so I could see my error.log file

this is my error.log file

2019/10/30 15:56:01 [error] 3570#3570: *1 connect() failed (111: Connection refused) while connecting to upstream, client: [SNIP - IP ADDRESS], server: woosik.me, request: "GET /favicon.ico HTTP/1.1", upstream: "http://127.0.0.1:2368/favicon.ico", host: "[SNIP - IP ADDRESS]", referrer: "http://[SNIP - IP ADDRESS]/"

please fix this problem T.T and if you need to get more information, write comment please :) thx.