Economics Degree pre-reading no A-Level

I applied for an Anthropology and Development joint honours degree but switched it to Economics and Development because I realised that I was more interested in economics. I haven't really done much reading into economics other than reading Doughnut Economics and I don't think its a good idea to go into the degree with no background knowledge in economics because I didn't study it for A-Level so I was wondering if anyone knows any good texts/ websites to give me an overview of economics and whether I would be behind starting my degree without having done the A-Level. I emailed the Uni and they recommended me Economics 12th edition by David Begg but its a big textbook and I don't really know where to start with it so does anyone know some good introductory topics to get a good understanding of economics.