The most important thing is testing when taking insulin. Are you using a note book diary or an app? I'd suggest a written diary til your reguime is a bit more cemented.
If you can eat at set times then it will make this big change a lot easier until you're no longer a novice.
Taking insulin can cover snacks too but depends if your an obese type 2 or not.
You will be able to manage your new regime better with a bit more framework which should be allowed to settle in before making further changes in diet and exercise.
Right.
Treat today as day 1 and establish if you've had a breakfast or not. Of course you're advised to have a breakfast but if skipped due to forgetfulness then try and use your alarm to definitely remember tomorrow. So if late in eating breakfast and due lunch then treat with lunch insulin. Get better and better at remembering 3 meals per day. Night insulin is always controversial as everyone reacts differently to it.
Myself at first usage of insulin I needed levermir and novarapid through pregnancy. I used levermir twice but maybe because of raising hormones and weight.
My advice is to try and keep just above good levels at the start, til you get a better grip and understanding of how YOUR body takes to the units. Then tweek as needed. Down or up a unit at a time if you're an adult. Try and avoid hypos as not pleasant but risky through the night.
Test test and test again to perfect. Don't take too much insulin before bed as a night hypo can be much more dangerous because of a few factors.
Lchf diet will help to keep hypos at a minimum and the need for less insulin and severe corrections, I feel.