There is a week long conference on TRP channels in Colorado in September, this is very relevant to my PhD so should I be thinkiing about going? I'm only a first year so a bit scared about being out of my depth and it being a bit scary. Also do you have to go to the whole thing or are you able to pick and choose which talks to go to? It is in a nice ski resort which would be good, but is it possible to take a partner with you? (obviously they would have to pay) I think I would be a bit lonely going on my own but think that is a stupid reason not to go.

I have a friend who just finished her PhD in schizophrenia physcology, and she went to a conference in Switzerland. She spend 2 days at the conference and 5 snowboarding! I guess you'd have to justify it to whoever is funding you, but if they say for you to go, then you may as well. Enjoy it!

No, you don't have to go to everything - no-one keeps tabs on you, but if it's some kind of scientific society who funds your conference fee (IF you can find funding - it can be very difficult) they'll probably ask you to write a short report when you get back.
I don't think it's silly not wanting to go on your own - I have the same problem since I'm in a very small group. Ask the conference organisers if they have a registration fee for an "accompanying person" - I've seen that some conferences (usually the bigger ones) do this, and will organise a whole programme of activities for your accompanying person while you're at the presentations.