Softwear for tune

Hi to everyone! I am new in this, and it would really help me if someone can tell me, what softwear i need to buy for tuning petrol engines with turbo and without, and diesel engines... Can i make that everything with one softwear or not? I want to start tuning carrer and hope ssome of you could answer my question, because everything till now what i saw in online lessons by HP Academy was Haltech elite 2500 for petrol engines naturally aspirated, Link G4+ for petrol with turbo, and till now i didn't look anything for diesel but i guess it is also different... So, it iss pretty expensive to buy for every type different softwear.. My friend is doing this for few yearz but i am not sure about his expert because he is using Magic Motorsport flex and tune cars without dyno, without driving on road.. I am not sure about that. Because with that you can tune whatever you want and dont need even to run motor... Also like begginer every advice is WELCOME!