I'm helping my dad convert 10 years of handwritten notes into digital format, then into graphs, and I'm getting very lost when it comes to the graphing part.

There are two formats I'm working with. The first is a spreadsheet with his gas expenses: I have price per gallon, the amount of gallons, the date, and the odometer reading. What he wants is to have a graph that shows over time how much he spent at each stop, what kind of mileage he got (km/100litres), etc. What I thought would work is a scatter graph where the X axis is time (either by date or distance/odometer) and the Y axis is price, with all the points on the graph being the location of the stop with the amount of litres. I don't know if the Y axis should be the price per litre with the total price paid in the point information, or vice versa, or if I should make a separate graph for the total price paid and the price per. I'm also not sure how to do it (I have been going through tutorials, but something is not sinking in and I am having huge trouble figuring out how to properly convert to a graph).

The spreadsheet currently looks like this: http://postimg.org/image/ntptyujwz/ (there are 2 columns each for amount and cost, for USD/CAD and gallons/litres, if you're confused at first)

The second is his 'journal' where he records his meditation sessions, his bodily symptom (arthritis acting up, etc), medications he's taken, if he took a walk, that sort of thing. He also wants this in a graph that shows changes over time, and this one is even harder for me to wrap my head around than the other one. I don't even know where to start.

This is what the spreadsheet for this one looks like: http://postimg.org/image/ojr1nu2ir/

If anyone can give me some hints on how to do what I'm trying to do, it would be greatly appreciated.