Since I never understood op-amps from reading or practicing problems I wanted to build a circuit to probe around and use different resistor values to set the amplification....
Just a word of caution - education is a process of diminishing deception. Books provide a simplified version of real World electronics. Universities and colleges put a lot of effort into designing lab practicals that will actually work and give the predictable results that students expect.
So the normal learning process when it comes to op amps - is to read and understand the theory. Then complete those crafted lab practical exercises - having been introduced to the added complication of systemic and random errors. Then do your own thing, when all the remaining Real Life complications hit you like a brick.
So, if you can find a course in analogue electronics, even a distance learning one, you might find the steps are smaller and more easy to assimilate.
What worked for me, that may not do so for anyone else - is to take an existing circuit (usually a reference one provided by a manufacturer) and build that. Get that working (sometimes, it hasn’t worked- the manufacturer’s technical support department has often been very helpful, especially when their reference design has a design fault or has been misprinted - after doing that, they used to send me unmarked, pre-production chips/etc to play with and provide feedback).
Then modified that design, to test my understanding. Tried different board layouts, guard rings, etc and documented the effect. When it didn’t work as expected - took that back to their tech support to see if we could work out why.
So, for me, taking something that works and keep modifying it, just a little.
Non-Inverting LM358 Circuit Not Working (discuss.tchncs.de)
Since I never understood op-amps from reading or practicing problems I wanted to build a circuit to probe around and use different resistor values to set the amplification....