Hello
First of when you say an 18 km and 39 10k you can do how many seconds as there is a bit of difference etween an 18:00 5k and a 18:59 (sorry if that sounds rude)
Either way looks like your 5k is your best distance compared to the rest
Vdot
That is the one i use, it could be the current training you do.
How long have you been running? What does the 30 miles consist of ? and at what intensity
I can't advice of specific training maybe someone else will as you are much faster than me.
Still its still a lot to take of in a year but like your enthusiasm
Are you a member of a club that would be good as well
Quite possibly you will need some more miles esp for the 10km (and probably the 5km)