What works for building confidence is different for everyone and some people naturally understand how to do some aspects of driving better than others.
This is what helped me personally.
I found this video for some reason is one of the best for understanding road markings*
https://www.youtube.com/watch?v=LBYzMAAPtqE if you acquire the skill of looking (observing) for and reading the meaning of road markings as you drive almost everything else falls into place - if you can get someone to sit with you and find a stretch of mostly empty road and practise just noticing the lines changing.
Then start looking for signs with red on them, for some reason it isn't the approach most instructors seem to use instead trying to approach understanding each sign individually, signs with red on them are telling you things you need to know and/or need to obey about the road ahead - once you start filtering what you are looking at by picking out and understanding signs with red on them - most are fairly self explanatory when you actually look at what is on them - you'll increasingly be starting to understand what you are looking at when driving and mentally processing what is going on. You can do it as well as a passenger which also helps to build up your mental approach when driving.
(The exception to this is train station signs - for some reason they are prominently red despite being purely informational hah).
I like to practise hazard awareness when driving - for instance saw a ball at the side of the road the other day and thought might be an indicator kids were around and be prepared for that, another time seeing dirt marks from a field into the road thought it might indicate agricultural traffic and as it happened as I rounded the next bend there was a tractor doing 20MPH.
Ultimately I'm still a **** driver though - I struggle with roundabouts (mostly because I don't cope well with other people doing unexpected things) and don't always have the right instincts when approaching a situation despite having had a license since 2001
* For me it was more a refresher as some things I hadn't really thought about in awhile but after watching it I had a much better mental awareness of the meanings than from when I learnt to drive.
I'm glad I learnt on manual - but I have no intention now of going back to a manual for road use - it is automatic from here on out for me - I used to be of a different opinion but the difference in how much stress (even though I didn't notice it as stress) built up commuting in a small manual car vs a larger engine automatic one is actually quite significant - but then I find driving stressful at the best of times - I don't cope with dealing with other people very well especially if they do unexpected things.