Hi Greg,
WELCOME along fella. I'm on the CW / WW border so in CW town at least once a week - so sure to see you around.
Love that colour and probably my favourite colour for a classic (RB5 like).
If the engine is running standard OEM config and map then 10w40 semi is what the dealer puts in and can confirm it works well.
As stated by others, regularly changing oil is important - if driven normally with the odd sprint here and there the interval is 10k miles or once per year (whatever comes first).
If you drive a lot where you'd clock that up in 6 months or less then that interval is fine, if you don't do a lot of driving and / or a lot of short runs you need to change more often.
If you drive her hard or have mods / remap, you might be looking at different oil grades and substantially shorter oil change interval.