Fix a destination based on your predilection as well as budget.
Look up air / rail prices and check the weather conditions that the place normally experiences around April.
You will need to pack smartly with an adequate amount of woolens/warm clothing to keep you comfortable.
Ensure you carry a good pair of shoes/boots fit for mountain climbing or snow walking.
Carry some over the counter medicines especially for those with motion sickness or tend to suffer cold and altitude sickness.
A leak-proof thermal water bottle, an umbrella to shield you from the overhead sun or snowfall, adequate cash and a power bank, should sail you through.
Book hotel / homestay/ resort as per your preference and ensure airport pick up and drop facilities are covered.