Take Your Time
Celeste is as much of a platformer as it is a puzzle game in ways. You have figure out how to reach certain points on different levels so that'll leave you to think a bit. The good thing about Celeste is that there's no time limit of any kind so it's pretty free-flowing.
Also, there may be some hidden paths along the way so make sure you're pretty thorough when looking around an area. These can lead to some shortcuts and other interesting things. Sure, you can just keep pushing forward, but don't hesitate to go off the beaten path.
Remember, there's no time limit, so you can really take your time. That said, I understand if you want to progress things along. At the end of the day, just know that the level is free to explore for the most part, although it's not necessarily an open-world game.
Utilize Your Dash Effectively
One of Madeline's powers is her ability to perform a dash move, which allows you to have quick movement, especially in mid-air, but only for a very short time (a second really) and can only use once in mid-air, only resetting after you land. And since this ability doesn't last, it's good to time your dashes as best you can in certain situations.
It all really depends on the obstacles that are presented in front of you. Sometimes you'll need to use dash as soon as you jump. In other instances, you may want to wait a second after a jump before using the dash power. And sometimes you don't need to jump at all, but just use dash to get across something.
Whatever sticky situation you're in, the dash ability is really your only main friend here that can help you overcome different parts of each level. The good thing is, you don't need to worry about how many times you die. It just gets added to your total death number (no big deal, right?) so there's no "game over" to worry about thankfully.
But, Celeste is a hard game, so you're going to die, especially on your first playthrough but dash can help ease the pain a bit. But if you're really struggling, feel free to turn on the Assist Mode which will make your climb much easier. Among other things, it will give you infinite dashes which can be immensely helpful.
About Those Strawberries
Throughout each level, you'll notice some strawberries floating around. There's no requirement to get them, but they just look good for your stats. I'd say that if you see one, at least give it a few tries and see if you can snatch it.
I will say though that it can be very difficult to grab these strawberries. They are usually in tight places that seem like they're almost impossible to reach but are possible. One example would be a strawberry that's floating on a platform that's high above a row of spikes. It would likely take a creative blend of jumping and dashing to reach it.
So overall, I wouldn't worry about grabbing them if you find them frustrating to reach. But as mentioned, you should definitely give it a shot when you see one because it doesn't hurt to try (well, besides falling to your death). But if it gets frustrating, feel free to just move along. You can come back to the level at any time and try again if you wish.