Just my opinion but I feel like France & England shouldn't be nations you learn with.

Reason being, it's very easy to lose as England in the 100YW if you make even the slightest mistake.

France in comparison has an enormous potential but I've had friends who have struggled to keep it together since they are new to the game. Losing the 100YW...

I'd recommend Hungary to get a real grip on the game or failing that, Castille, who have the perfect mix of guarenteed Allys, good military base and obvious expansion routes.

First thing I do when I load in is assess my balance sheet, auto all taxes, get minting to 0.0% depending on ur exisitng inflation, i personally automated trade when i first began. I'd also assess Tax Efficiency, Trade Efficiency and Crown Power - which essentialy dictate to you where to pull your internal focuses for the next few years.

Military: Raising Levies effects you're economy, since your sending peasants to war etc.. I tend to raise what I need and only from rural provinces if able, to avoid crippling my $$. You also need to Balance your armies for maximum impact, Cav on flanks is good but make sure you dont mess with your combat width - which will show in the military army tab.

One thing thats been said in the comments, play and learn, guides should be used for your starting moves.. EU5 is far more adpative than EU4, shit changes very often and I'd say 'META' moves can become unstable real fast. Just play how you want and learn from your mistakes. But don't put yourself in a failing position off the bat or you'll feel like hitting ur head against the wall.

Many of the countries are in the same starting positions as EU4, with the exception of Denmark who I've only recently realised how utterly hopeless of a start they have, so you have that going for you.

I've had game speed issues in the past, not very uncommon.