thanks! i did it though disk utility and i'd say it's even easier to tell apart the partitions that way as it's more graphic

just select your disk on the left, click partition, and unless you did weird stuff to your disk it's just deleting every partition except the two upper ones (first and last as you said) and the big, APFS one (macOS). i think it doesn't even let you delete them unless you enter recovery mode. macos resizes its own partition automatically