Welcome @NippyNinjaCrab. Small weights are ideal for beginners (can be dumbbells from 1-5kg, tins of beans, bodyweight). She has an ultimate beginner workout series on her paid app where, unusually, she talks her way through what you should be doing,
(her youtube stuff has no verbal cues). Getting the form right is the first priority to avoid hurting yourself. Your muscles will strengthen much faster than the supporting tendons, so take weight increases slowly.
Speaking of, I seem to have slightly rejanked my janky elbow playing a little beach cricket yesterday so no upper body for a few days. I was going to have a Caroline-focused week but might just do one or two lower body days along with cardio. Step aerobics is perfect for when resting upper body injuries. Any lower body CG recs? You all make me want to give PE a revisit...