If the wheel is not straight and the chain a bit dry then that could cause the noise.
With the bike on the centre stand, spinning the wheel will tell you if it's aligned correctly or not. The chain should quietly purr when it's right, but if it's not straight then you'll hear all sorts of noises.
When adjusting the chain slack don't forget to slacken the brake caliper bar, and take your time nipping up either side a tiny bit at a time then spinning the wheel to hear if it's okay.
You want roughly around 35mm of play at the lower middle part of the chain, or a quicker and easier way is pushing the front of the lower chain upwards with your finger and it should just touch the plastic chain guide.
Having it too tight is just as bad as having it too loose, so get it right then you won't need to adjust it again for ages.
I've started using a paint brush with engine oil to lubricate my chain now, instead of spray lube which i used for decades, and the chain is in better condition than ever. Plus it doesn't clog up any more, it repels dirt, and the oil effectively gets into every link when applied when the chain is warm after a run plus only takes a maximum 2 minutes to apply. I have newspaper down in my garage to catch any drips, and any other excess gets flung off next time i ride it.