There's a couple of more in-depth explanations already on here to help with beginners, but some personal tips that help me a lot in the beginning is these sorts of things.
1. Use and experiment with different commanders and don't try the more difficult things like breaking core t1's unless you have a proper plan in place.
2. Try to conserve your EE unless you have a good plan you want to work towards like causing a rivalry or a specific t2 break.
3. Pay attention to the minor vulnerabilities on your chosen and use them to as a starting point to getting some good damage. Ie. A chosen with a minor vulnerability in Confidence is very weak to INJU damage so try to raise that first and then plan from there. otherwise if they have a difficult vulnerability to exploit, target a weaker chosen first before you go to your main target.
4. Use your commander at the start of the battle and get some decent damage on a chosen before the battle start, prioritize either HATE or INJU in the beginning to begin raising damage properly.
5. Networked Consciousness is an incredible upgrade and I personally aim to unlock that first in any run.
And I would recommend going through the full 50 day run even if you know you will lose since completing a run unlocks easy mode/cheats. And playing in a cheat mode is a good way to learn the game mechanics since you can start with everything unlocked and unlimited EE.
If you'd like you can also post your team here and someone can give more specific tips as well.
Overall I hope this helps a little bit and you have fun with the game!