Facebook

You don't need to go on Facebook if you don't want to.
If you get directed to a trade website on Facebook, you can look at the trader's website without joining Facebook.
Alternatively, look at local websites. Try search for terms such as 'painter and decorator near me.'

You don't have to use your own picture or date of birth. You can lock down your profile to limit who can see the information you post. This mean that you would be able to join local residents' groups, for instance, or use Facebook Marketplace, but you can still keep your privacy.

I'm on Facebook and have two accounts. I use two different email accounts and different names. One is for close friends and family, the other is for my sewing hobby. I just have one friend on that one - my sewing mad sister. I join whatever groups I fancy and can easily delete if I don't like them. It's great fun to see other's makes and get lots of tips. There's no need to befriend anyone nor post pictures or comment at all.

People can only see what you post. So if you do not post anything no one can see anything, but you can still join groups and look for traders.

You choose who you want to be friends with, and you can unfriend someone if you change your mind, also you don't have to put any personal details or pictures.
For local information you can choose to join pages, and also most of the big companies have pages you can look at or leave comments on - can be useful to see what people think of them.

befriending people I don’t know, and posting pictures of my activities

Why do you think you have to do this? I’m on FB, I only have a few chosen ‘friends’, I certainly don’t befriend all and sundry who may ask me to, and I never post pictures of my activities.

No one is forcing you to do any of this, it really is your choice.

I am on Facebook. I use it for local information only and it is useful. I don't post and my profile picture is a sunset. There really is no need to share anything at all. My handful of friends are family members but we usually communicate on WhatsApp.