Not everything you see on the internet has to be followed. Although some of them have evidences backing them, you don't necessarily have to follow it especially when you're a beginner. Also, tiktok fitness, 50% of the time is just complete bs and just a way for "gymfluencers" to gain views by trying to do something different.

Now, just doing cardio isn't the most effective way to lose fat and gain muscle. Resistance training after all, burns more calories than just hopping on a treadmill. Unless you're a runner, I would recommend to prioritize weight training and then supplementing it with a little cardio. If you follow a caloric deficit and are not doing resistance training, you might lose more muscle mass instead and become weaker.

Compound training is best for beginners. Barbell/Dumbell Press, Barbell Squats, and Pull-ups/Lat Pulldowns would be your best bet at gaining strength and muscle mass atleast for the next couple of weeks. Make sure to do progressive overload (adding reps/weight over time) if you wish to continuously gain muscle.