The topic "DSA" is not Rocket Science but can do revolutionary things when implemented properly.
To learn DSA you need to first understand the following things
Understand how programs use computer memory to store data OR how computer memory stores data.
Start with Array, just array; not any programming-specific perspective, just understand what array looks like; for example: ceoOfMNCs = ['Elon Musk', 'Tim Cook', 'Sundar Pichai']
OR it's a simple list of CEOs of MNCs having Elon Musk, Tim Cook, & Sundar Pichai as three data elements.
Understand 4 basic operations of any data structure: Read, Search, Insert, Delete & understand how they relate to Computer Memory.
Don't jump to the Big O Notation thing directly.
Let's understand Array 101 with our ceoOfMNCs example array:
the foundational Data Structure and a list of elements.
the counts of the elements in the array begin with 0; So, for our example array ceoOfMNCs, the elements "Elon Musk" is at index 0, "Tim Cook" is at 1 & "Sundar Pichai" is at 2.
index of an array is the number that identifies where a piece of data lives inside the array.
basics of programming like conditions, variables, loops, etc. (not any specific language, just concepts)
what arguments you're taking as input parameters?
what type and data you're returning?
steps / algo to perform operations or solve a problem.
each step & statement like printing the value, comparison, etc. & debugging so that you can seriously understand what's going on in the code you're writing