Question about soil types

[AcerTree]

If I want to grow plants that need acidic soil in my garden but my soil is more alkaline, do I just need to add different soil/peat/compost to each planting hole?

You will need to add iron sulfate to the top soil around each plant. Dig it in a couple of inches and if you are planting a new plant add the recommended dose to each plant hole.
Or you could buy sphagnum peat to plant in and add to your top soil.
Both you will find in any garden centre.

That sounds easy enough! Thank you so much for replying.

It depends on how alkaline your soil is and which plants you want to put it. Some plants just won’t tolerate alkaline or may not do so well e.g. not flower. The RHS website is very helpful - search on each plant and it will tell you if it can survive in alkaline soil. Once the roots get established and deep they will feed off the alkaline so it’s worth checking.
www.rhs.org.uk