Как по английски-всего доброго

All the best. Wish you all the best. Have a nice day.

Hello, my dear friend Jack. I am writing to you, in order to invite you to my place. I miss you very much. I want you to come to London and we can see each other. When you finish your classes, come and we shall spend much time together visiting different places of interests in London. We can go to park, have walk, or we can go to sightseeing. You will see the main attractions of London. I shall be very happy to see you and I hope that you will come. I am waiting for you.

Wish you all the best, your friend John.