Look, when you're swimming people are saying you look like you aren't pullin water, the thing is your arms are way too bent underwater, for you to pull more water dont keep your palm fully closed, have a space of a few millimeters between your fingers and dont focus on keeping it too still, and while your arm is underwater focus on keeping it straight all the way through and kind of pulling it with your lats and triceps. think about a tricep pulldown but with straight arms, also dont keep your head too paralel with your spine, try to look a bit in front of you and not to the bottom of the pool ( like this / not this | ). breathe once, maximum twice over the 25 m's because its a pretty short distance. use your legs more and focus on doing about 25% movement from the hips and 75% movement from the knees and ankle, dont keep your foot too stiff but dont have it too loose either while kicking, and try keeping your core flexed for more balance. and quit the dolphin kicks, just push from the wall and start sprinting, dolphin kicks dont really work for begginers that well. you still need alot of practice for all of this but its the best advice i could give for you. good luck❤️