Here is a popular travel plan for those entering via Jaigaon/Phuentsholing.
Cross the India-Bhutan border at Jaigaon. Complete permit formalities. Overnight in Phuentsholing.
The capital city. Visit the Buddha Dordenma statue and the Motithang Takin Preserve.
Visit the National Memorial Chorten and the Folk Heritage Museum. Experience local culture.
Drive to Paro. Visit the Rinpung Dzong and the National Museum of Bhutan.
This is just a sample. To get a fully customized plan including hotels and driver costs: