When I started, my UK secondary school (state Girls’ Grammar) only taught French (from age 11) and Spanish (from 12) and Latin (optional, taught in lunch breaks). Some students had learnt French for a year or two at primary school, but they all went to private schools, I’ve never come across any other languages as an option for English state run schools prior to age 11. The situation is different in Wales and Scotland, but I don’t know the ins and outs there.
At age 13 you could choose to drop either French or Spanish, but at least one modern European language GCSE (exams taken at age 15-16) was required.
It changed while I was there, however; my year was the first to be offered German as an alternative to Spanish (scheduled the same time, so you couldn’t take both), and the last to be offered Latin. I took both German and French to GCSE, as well Latin until it was unexpectedly discontinued a year into the course.
You got me curious to check the current language offerings, and French, German and Spanish still seem to be the standard minimum for every school in my old area, with a few random other options here and there.