My general recommendation to excel in IM is to pick a resource and consistently study. Since most of us take STEP 3/COMLEX 3 during intern year, your initial goal should to just study to pass. I took my exam in October of my intern year and all I used for this was Anki and UWorld and did fine with not even completing UWorld and only studying 2-3 weeks
After your done with Level 3, give yourself a month or 3 to chill and try to catch up on how to be a good intern (which can be hard)
Around December of my intern year I purchased MKSAP individually because I felt I wasn't learning the key points on rounds/during lecture that my peers were
After buying MKSAP I would do blocks of 10 questions per week CONSISTENTLY and every once in awhile do an extra block or so on topics I had learned that week in the hospital
I tried to pick questions that related to my patients and understand why attendings/residents don't do what MKSAP recommended and tried to talk to my attendings/peers about these differences to reenforce my learning. I felt this really helped my learn what was important, what was testable, and what was more clinical practice
By the end of intern year, I was getting bored with MKSAP so I started doing the MKSAP ANKI which helped solidify the information I had already learned and retain what I could. I'd say I did about 50% of the ABIM and MKSAP decks during ALL of second year. Went very slow and tried to look up a concept a day (related to patient care), mainly using them for reference