Automatic spelling correction when composing in French in Mac Mail

I am having a tough time composing a letter in French from France. Primary language is Canadian English, but as I am typing I expect that when I write a french word that I know has accents,, to at least be underlined so as I can correct.. Doing it that way seems to be unreliable, as it is hit and miss in recognizing or flagging words that need correcting , where I can right click,, and replace with word with accent. What I would like even better is for me to type (using my Logitech for Mac keyboard bluetooth) and for it to automatically correct or know that I am typing in French. I have gone to Language and Region,, put Preferred language Primary English Canada, and added 2nd preferred language as French France. Keyboard Preferences,, I put Canadian English,, there is no French Qwerty keyboard that I noticed, so I did not add as an Input source.I'm sure ,, in my many years on Mac,, at some point I must have had settings correct,, and somehow,, things have gone astray. Once in a while,, when experimenting to get it right I see the Can Flag on top menu,, with opportunity , I think to change keyboard,, (that is when I tried to add that French Keyboard that wasn't qwerty), ended in disaster. Hoping somebody out there can help. I also in Edit,, I think done the right things I think,, like Check spelling while typing.. Thanks,, I you need more details to help me,, just let me know. Appreciate it.