A nice simple phrase, but there are some useful points. The “oo” in “look” needs to be very short, like “put”, not long, like “food”. The “t” in out can be pronounced fully, or down where your voice is, as shown here. The most important thing is that there’s plenty of stress on “out”, and big intonation, because this is a warning.
We also say “Watch out!”, with the same meaning, warning someone that they may come to harm if not careful, for example, “Look out, there’s a broken step.”
The way to link “just” to “found” is simply to skip (leave out) the “t”. The diphthongs (double vowels) can be difficult. You can practise them separately. Notice the stress is on the preposition, which may be surprising, but is very common, particularly with a phrasal verb. The final “t” is often pronounced not with the tongue, but right down in the throat, where you make a /h/ sound. This sound, which looks a bit like a question mark, is called a glottal stop.
“Find out” means “discover”, so this phrase means “I’ve just discovered/heard” some news or information.
Remember that the -ed past simple verb ending usually has a silent “e”, so it doesn’t add a syllable. Because of the /k/ sound, the “d” becomes unvoiced – /t/. Curiously, the “t” of “it” can be voiced, making it sound like a “d”. This is optional. The final “t” can be pronounced with the tongue, or down where you make a /h/, but isn’t released.
To work something out is to solve a puzzle, mystery or problem.
Notice that the “ed” ending of “worked” doesn’t add a syllable. The “e” is silent, and the “d” is unvoiced, so sounds like a “t”. Also notice the pronunciation of “the” when it’s followed by a vowel. It’s quite different from the dictionary pronunciation.
This phrase means “It ended well”, and you would say it about something you had been worried about, like a difficult exam. My students have exams this week, but I’m sure it will work out OK in the end.
Notice that “I”, when unstressed, can reduce to the short vowel /ʌ/. Because of the “m” of “make”, the “n’t” of “can’t” is pronounced with the lips, not the tongue. There is a stop between the words, but don’t open your lips. Listen and practise. The “h” of “him” is tricky, so we just miss it out.
“Make someone or something out” is a phrasal verb meaning to see or understand clearly. It’s often used in the negative. This phrase means “I can’t understand him well”, or “I don’t know what to think of him.”