Confusion about a boy?

[Georgia]

Here's the thing... I have liked this boy for almost a year now. He doesn't go to my school, he goes to my athletics club, and it's unpredictable when he goes, so I usually only get to see him about once a week.
We don't talk aaaall the time. I get too shy and sometimes we don't speak at all at sessions, sometimes we speak quite a lot. I am just soooo confused about the signs, all these things on the internet confuse me, I mean how can I try to spot his pupils dilating!!??
I really really like him and any help is appreciated. Last week we went on a long run and we talked quite a lot. He then liked my photo on facebook.. And trust me he NEVER does anything to anyone elses profile, and is barely ever online. He voluntarily stands next to me in warm ups and is usually the first one to talk to me if we do talk. Some days we talk loads, some none at all. He barely ever talks to any other girls but me. He is also very shy btw.
Thanks for any help, much appreciated!!!!!:)xx