Not Started For A While!

The bike I'm restoring hasn't been ridden for a couple of years and I know there were electrical problems with it (immobilisoer etc.) when it last worked.
There are a few more things wrong with it now i.e. no ECU and no keys and a bit of a chopped up wiring loom.
Question is, once I've got those replaced, would you have a go at starting it to see if the engine / wiring loom / ECU etc. are all working or do I need to:

Change the oil (I'm thinking yes!)
Fresh Petrol (may as well)
What about belts etc...??? is that necessary just to see if it will start - is it taking a risk if I don't??? I'd def look to change the belts once it was all up and running, but just wondering if it's necessary just to see if it will start.

Is there anything else I should change or check before trying to start it?

Cheers

 

NB Reason I'd rather not change the belts initially, is I'm not sure if it's something I can do myself (or would I need special tools to do it)?
Getting it to a shop to do it for me won't be straight forward if it doesn't ride!

In my ideal world, I'm hoping I can change the electrical bits etc. start the bike and ride it down to the workshop where they can service it and change the belts etc. for me and then I go back to restoring the rest of the bike. But I don't want to take any risks if there's a significant chance it might bugger up the engine!!! just after your thoughts! What would you do?????

 

Yeah good point, thanks Grey, may as well have a look see what they look like!
Cheers

 

Stupid question coming up... What does that do? Show you've got oil pressure???

 

Thanks Exige, nice one! I'll def check those out, looks like a lot of vids there that will be useful to me.
Cheers