Creationist is the term used to describe anyone who believes that the Bible describes the literal truth about how the Earth and its inhabitants got here. Creationists have their own school system in the UK called ACE (Accelerated Christian Education) which Johnny Scaramanga has spoken out about.
Creationists have a much larger impact in the US. Ken Ham - a prominent creationist - opened a creationist museum in Kentucky which features an ark and humans riding dinosaurs with saddles on. He has debated many prominent science communicators and atheists, like Bill Nye. Creationists have a huge influence on politics in the US. 68% of Republicans don’t believe in evolution, as opposed to 40% of Democrats. Creationist support in the UK is a much more reassuring, though still far too high, 22%. There are regular disputes about evolution being taught in schools in the US.
Common creationist arguments are the watchmaker and appeals to the “missing link”. The concept of deep time needed to be able to understand evolution is difficult for us as humans to understand. Due to this it's easy to see why it’s easier to get your head around creationist ideas they make sense in the way we as humans experience time. Another misconception is the public idea of what a theory is in science compared to colloquially. Most people think a theory is just an idea that is still to be tested. In scientific language that would be a hypothesis. In scientific language a theory is a hypothesis that has been tested and proven with the current evidence. Scientists never talk in absolutes though which is right but can be both wilfully and unintentionally misunderstood.