External Monitor Setup

Hey guys, 

I just got a new job in Deal Intelligence (M&A) after working in the back office as a Research Analyst for 7 months. Had some queries and would like your opinion on the same. Please find them below - 

1.  I currently use the HP Envy 13 laptop with Logitech MX Master 3 mouse. Till date its running smooth but the only issue I'm facing is the screen size which is 13.3 inches. Do you recommend i set up an external monitor to connect with the laptop. Will it increase my productivity since i have never used a dual monitor set up before. 
And any tips on what factors should i keep in mind while setting the dual monitor (if you recommend i do) 

2. Should i also use a laptop stand for the same? Since i think if i use the additional monitor, it should be on the same height as that of my laptop. And lately been facing some pain in the neck due to sitting for long hours. Will a laptop stand effect my productivity ? 

3. Which keyboard should i use along with the dual monitor setup ? Looking for something which is value for money ..... contains a number pad and can improve me increase my efficiency.