The title says it all never played the game before so I'm asking if you guys have any tips about the game. Thanks in advance!

Don't be too worried if you get pretty deep into the game and then realise that you may have to restart completely.

Yup, what @lilman1101 said can be true, there are times where you'll have a run where the only units you have a bunch of new guys who aren't worth shit and only a few countries supporting you and even they are going to want out pretty soon. It can be tough, but addicting, and you will absolutely learn from your mistakes.

As for general tips, I'm sure you''ll carve your own path of what to do eventually, but I've found these helpful on my runs.

Don't let your units get too far away from each other, if one guy goes too far ahead or across to the other side of the map and doesn't have any buddies to back him up then he's screwed usually. I don't even like to let my guys get into the 'red' movement zone, I like too keep them in the blue and make sure I end my turn with them doing something useful like being in over watch mode or hunker down or just something you can't make them do if you are in the red.

Sometimes you'll get a mission where you need to research or upgrade something in order to continue the general plot of the game. I like to putt off doing those sometimes, they wont go anywhere and you can then research other stuff or continue to send your troops on missions to hopefully improve them without worrying too much about the next big enemy type.

Make sure you have a nice reserve of troops, if a unit survives a turn but takes lots of damage, they will be out of play for a while until they heal, you don't want to end up in a position where a mission comes up that you need to do and you only have 3 guys to do it or something.

Also, I feel like the game never states this, but maybe it did and I didn't notice/got distracted, but you can sell shit you don't want/think you'll need at the black market, which can really get your ass out of a jam if you need that last minute gear upgrade or until or whatever the hell you need.

So those are the tips that I personally find useful, but it's the type of a game where someone may come along and go "What?! That's ridiculous! This is how you do it instead!"
So really, if you treat the game like something to lose over and over, it can help, heck, the only reason I finish my first 'win' of the game was because I got as far as I had ever gotten before and started to save spam my battles so whenever I lost a guy I reloaded because I just want to see the ending god dammit.

1. Always hide behind full cover if possible (when the shield icon is full).
2. Keep multiple saves in case a mission goes bad.
3. Do the tutorial to get all the basics down, then start a completely new save and skip the tutorial so you can choose your own continent to set the HQ instead of the fixed NA one.