How safe is paper or plastic money notes or metal coins that we all hold in our hands when exchanging them for goods..same with credi cards

Safe as always.  Will you please pass the poop? xD

Coins are semi-safe as the have free electrons that can kill micro-critters. I wouldn't put them in my mouth, though. Currency is filthy, as you can imagine, being passed around from person to person. I'm not sure about credit/debit card, except I am the only one to touch mine.

We OCD agoraphobic germaphobes have told people this for years.  But did you listen to us?   Noooo!  
(and once you disinfect something, you have to re-disinfect it just in case the disinfectant is infected.          Welcome to my hell!)

When I come in from shopping, I remove my shoes, coat, scarf and gloves, and wash my hands then wash the front door handles.  I then unload my shop, put bleach and washing up liquid into my washing up bowl, and I wipe everything down and put it in the cupboards and fridge, then bleach the side down.  Yes my kettle handles, all handles, taps get bleached.  I wash my purse, car keys, my mobile and my credit card, and my handbag.  I get a bowl of bleach, and wipe all the outside and handles of the plastic carrier bags and hang them in the bathroom, I then mop the floors.  Thankfully I'm only shopping once a week if that.  I do wash my remotes etc, but not daily, if you keep your hands clean then things inside should stay clean.  I've used watered down disinfectant on money and plastic notes and it doesn't harm them, but I've been wearing gloves when out, so I take money with gloves and give money with gloves.