I want to become a software engineer.How,steps,courses,college,everything????

If you want to make a career as a software engineer . After 10th std , you need to apply for science stream , since you have already decided your career as a software engineer you should apply for computer science or information technology as your vocational subject . Then you should prepare for engineering entrance exam like JEE MAINS AND ADVANCED , BITS, NMAT  etc:

Then you should apply for best engineering institiutes in india like IIT , NIT or apply at any private university like Symboisis, Nmims university etc : Get a good score in it and get a placement in a company as a software engineer .

Here is the link for all engineering entrance exams : https://engineering.careers360.com/exams

You can also apply for other computer related degrees like bsc in computer science  , bachelor's in computer application  etc : But for the fields mentioned now , an entrance exam is not compulsory , it may be depend on some university but mostly there is no entrance exam for the mentioned courses . But you have to take science as your main stream and computer science or information technology as your vocational subject in std 11th and 12th  .

After that you can also apply for masters courses like Msc in computer science  , Masters in computer application ,  Master's in technology etc :

Here is the link for computer engineering colleges in india : https://engineering.careers360.com/colleges/list-of-computer-science-engineering-colleges-in-india

Here is the link for top bca to mca colleges in india : https://it.careers360.com/college/best-fit

Here is the link for details about bsc in computer science : https://www.careers360.com/computer-science-course