Low coolant level - paranoid ;)

Hi all.
Quick rundown;
Bought my 2010 FL2 over a week ago and am very happy with it.
The only small problem with it is the parking sensors don’t seem to work but the garage I bought it from gave me three months warranty and said that being as I live over an hour and a half away I can take it to the local garage / dealer to get a quote and they’ll pay for it.
However, call me paranoid but it had a service before they sold it me, admittedly only oil and filter change and cam belt and water pump, and I got the ‘Low Coolant Level’ warning indicator this morning so am now paranoid about a head gasket issue.
My questions are;
1. I don’t want the garage to have anything to moan about so is there a specific ‘ideal’ antifreeze to top up with?
2. Is there a way to check the head gasket pressure?
I only ask this as I’m keen to not let the warranty to go to waste.
Cheers guys.

The head gasket issue is most commonly seen in the, FL 1, 1997 to 2006, and specifically in the earlier K series 1800 engine. I'm not aware of HG issues with the FL2. Top up with the same as what's in it. Other wiser peeps will comment soon.

Signs of HG failure include: unexplained coolant loss, a mayo-like substance in the coolant bottle, under the oil fill cap and on the dip stick; it's an emulsion of engine oil and coolant. Bubbling in the coolant bottle due to exhaust gases.

If it's had a replacement water pump, then the coolant loss is most likely due to any remaining air being purged out in use. Sometimes it can take weeks for all trapped air to purge out. Just top it up with whatever colour coolant is in there.

The FL2 isn't known for head gasket issues, so I doubt it's that.

As HTR says, if the coolant looks like coolant and the engine oil looks like oil, top up and see whether the level falls again.

It never harms to look carefully for leaks from hoses/ connections. There will be an under tray beneath the engine, so that'll make tracking down a coolant leak harder, but if it is dry, then chances are that there is no leak

I'm guessing the coolant is red - in which case, top up with an OAT-based coolant/antifreeze mix.