Best template for Poster presentation :First time(Conference)
Definitely worthwhile looking at previous posters from your conferences and other plus hunting around for posters from your department and team. There are some good sites that go through the background and with more concrete suggestions. 

For a more traditional style of poster - https://colinpurrington.com/tips/poster-design/

There has been a spate of new poster styles if you are feeling adventurous - London School of Economics

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