well Liam, Thanks for your support I solved my problem browsing from internet . I was try around 6 times by downloading Shopify cli 3.0 after that I set-up my OS .Then i install all the necessary things which is important for set-up cli i had install extra one thing which is yarn i think it helps me and i was login with my terminal just only my store name not full store link . all things helps me a lot. well i want from you some warm advice as a beginner which is the best i should follow to become a successful theme developer and please mention my step by step process. Thank you so much Brother.