Hi nomorecakes and welcome to the forum.
🙂
I notice that nobody else has actually explained basal/bolus yet? Apologies if you already know this (now!) but basal refers to your background insulin requirement, due to the glucose that your liver trickles into the blood; bolus is the additional insulin required to process food, as it enters the blood stream (MDI = Multiple Daily Injections). Basal is slow-acting and bolus is the fast acting insulin.
As others have suggested, using a mixed insulin means that you need to eat controlled amounts at set times, to match the insulin that is already in your body. It is not unusual for newbies to start on this regime, even today, as it lets you get accustomed to the new world of diabetes (blood tests, carb counting, good/bad foods etc), especially if you have a "honeymoon" period during which your pancrease may have odd spurts of producing insulin.
MDI gives you greater flexibility and lets you alter your insulin to match what you expect to eat - and, yes, cakes are possible!
There's a lot of stuff to learn, but none of it is particularly difficult.
Just keep testing, analyse the results and ask lots of questions.
Good luck.
PS. my auntie was diagnosed T1 at 65, after a lifetime of struggles with weight. Although she was perplexed by the barrage of info, she has now settled into it and lost some weight!