Leaking oil and tempature gauge always reading low

[SaucySaab]

So my first question is the oil leaking out of the https://m.imgur.com/U5TXM9i , https://m.imgur.com/6sAAcIs (?) Is that caused by a cracking head gasket?
My second question is when I’m idling my temperature gauge is a normal tempature but when I’m driving it goes cold on the gauge , all my fans are running fine and I just bought a temperature sensor but I haven’t put it in yet. I’m also wondering if these problems are connected

[Digger]

So my first question is the oil leaking out of the https://m.imgur.com/U5TXM9i , https://m.imgur.com/6sAAcIs (?) Is that caused by a cracking head gasket?
My second question is when I’m idling my temperature gauge is a normal tempature but when I’m driving it goes cold on the gauge , all my fans are running fine and I just bought a temperature sensor but I haven’t put it in yet. I’m also wondering if these problems are connected

First is a leaking cam plug, not related to other problem and an easily resolved annoyance if you have the tools to R&R without pulling the valve cover.
Second could be temp sensor and as you have a new sensor might as well put it in. More likely cause would be engine thermostat and if the temp sensor isn't the problem that is where you go next.