I just bought a S8 and had an iPhone 5s, I removed the Sim card from my 5s and put it in my S8 now I can't connect to my cellular internet?

And I also can't send messages or phone call please help me thanks alot also my Carrier is MetroPCS

S8 and Iphone5s are made by different companies. Sim cards are made model specific, you can't just switch it out into any phone

Your phone should of included a new sim card. The sim card is not compatible and go to your local metro pcs retailer and they will give you the correct sim card.

Your service provider should be able to help.
Go to one of its stores in your area.

Time to call MetroPCS. Only they can fix that problem.

Should contact your carrier about that. Assuming the S8 is not either unlocked or locked to metroPCS that could be your problem right there