What important things should I have an opinion on in life?

To be able to hold a conversation on things. Any important topics?

God, the EU, current affairs/foreign policy (ISIS, Russia/Crimea), nuclear weapons, financial policy, politics, climate change. There's a start.

What about the eu? And politics is a bit broad. But thank you that's actually v helpful

In, out or shake it all about? As in, should we stay in, leave, or renegotiate (immigration control, CAP, bail-outs etc).

Politics is deliberately broad as it's a broad subject. You should have a rough idea what each major party stands for, or is meant to stand for, how likely it is that they'll do well in the next election, who you'd vote for etc.

Aww thank you. Just making a list. Will read around all the topics every day. Thank you

You don't need to have an opinion on anything if you don't want to, and you don't need to explain to anybody why you do, or do not, have an opinion about something.

If you want to have an opinion about something, then sit down and think seriously about the topic, and decide what sounds right to you. But nobody is forcing you to do that at all. If you want to coast through life blissfully nonchalant about things, that is your right.