How to give Efficent,better,latest Datatypes in sql server

Question

Hi, I am new to database architecture.I have multiple table to create having different datatypes.I need some suggestion and clarification before I start.sql server 2017 i am using.Please help me on folowing topics

 

1.I would like to use Latest and better datatypes for my table 

 

2.what are new data types in sql server

 

3.How to decide the length and datatype of a particular coloumn efficiently? 

 

4.how i can efficiently put more length on a coloumn?

 

5.