Cant play on joypad properly

Ok, as to aiming with a controller, there's a few things you need to keep in mind.

You will NEVER twitch-shoot, the mechanics of a controller just don't work that way. Sure, you can up the sensitivity to max, but it will never be the same. You might actually want to consider lowering the sensitivity until you adjust to the sticks.

Strafing. Take advantage of the controller's SUPERIOR analogue movement. Fine adjustments of aim actually come from moving your character, not your aim. This will also take some adjusting to, as it's not just a mechanical change, but a mindset shift. This is also the only way to obtain fine adjustments with a high sensitivity setting.

Recoil. Recoil is a b*tch on controller, especially guns with variable recoil, or recoil "patterns" that aren't just vertical. You will have to re-learn recoil control, and the "delays" and "deadzones" involved with trying to counter-act it with a controller.

Muscle Memory. As a Mouse aimer, this will truly be your biggest bane, sticks just don't work the same way, you'll expect them to behave similarly, but they don't. Once you adapt to the sticks initially, you'll start expecting it to stop on a dime the way a mouse does, but it just wont, and you'll overshoot a lot.

Best way to adapt that I can suggest is find a difficult Racing Sim (yes, I know this is totally different), one that forces you to lead-in and fade-out with the steering (Just like in a real car, your wheel isn't suddenly at full lock, or instantly straighten your wheels, your have to gradually move it there). This will help you adapt to the way a controller accelerates and decelerates in relation to stick movements. If you just can't stand this kind of game, head to SP of a Mass Effect game where it is a little slower, and a little less taxing, and practice.

I say this as a PS player, who uses a controller on PC. On ME3, I'm primarily a sniper (yes, with a controller, even on PC's 60fps). I do, admittedly, struggle sometimes when sniping in MEAMP, though.

Putting aside the obvious mechanical advantages/disadvantages of each setup, this mostly comes down to "what you're used to."

Most games use one of a few mostly consistent control scenarios, the most common of which are "WASD" and "Twin Sticks." The advantage when switching in Mass Effect is definitely from console to PC, rather than the other way around. When switching to PC, you switch to one of those broadly generic configurations, and you can tweak or change it with keybinding to make it even more comfortable or familiar.

But when switching from PC to console, you're adopting a control scheme that is really specific to Mass Effect, and you can't change it (in Andromeda I think you can bind your three powers to three buttons, but that's it.)

The ME joystick control scheme is fairly different from other TPS' (for example the "everything button" in ME 3.)

I don't have much advice for you, other than that the key is probably practice and getting used to it. I wouldn't normally recommend the SP campaign of Andromeda (especially to someone who has likely already played it) but it would probably be the easiest way to take a few hours to get used to the controls without the frenetic-paced frustration of MP clouding the process.

I'd be curious how that would work out for someone specifically moving from PC playing ME 3. Actually, I'm not sure if ME 3 is even playable on PS4 since I think they dropped the whole "backwards compatibility" thing, which would make my point pretty moot. But I bet it would still be weird, because even with keyboard inputs, I think the turning and running mechanics would still function like they do when playing with a joystick. In theory. If one could even play ME 3 on PS4 which I'm pretty sure one couldn't the more I think about it.

Oh, I knew that. I was speculating.