Hello! Sounds like an exciting adventure in beautiful Spain, visiting Barcelona, Valencia, and Alicante! Here are some travel tips to make your journey enjoyable.

Best Time to Visit:
The best time to visit Spain is during the spring (March to May) and the fall (September to November), when the weather is pleasant, and crowds are fewer. These periods will provide perfect conditions for sightseeing and outdoor activities.

Route and Accessibility:
All three cities are well connected with both domestic and international flights. Barcelona, being a global city, serves as a good starting point. You can then take a train or bus to Valencia and then move further south to Alicante.

Accommodation and Booking:
All three cities offer a wide range of accommodations, from budget hostels to luxury hotels. It's recommended to secure accommodations well in advance, especially during peak seasons. Booking platforms like Booking.com, Airbnb, and Expedia are widely used.

Clothing and Essentials:
Lightwear is suitable for summers, while it's advisable to pack some warm clothes for evenings in the spring and fall. Do pack a good pair of walking shoes, sunscreen, a versatile jacket, sunglasses, and a hat. Don't forget your EU-compatible power adapter for electronics.

Health and Safety:
Spain is generally a safe country. However, always take standard precautions: Avoid carrying large amounts of cash; keep an eye on your belongings, especially in crowded places as pickpocketing can occur; in case of emergency, dial 112.

Local Etiquette and Respect:
Spanish people appreciate polite manners. Ensure to greet with a friendly 'Hola'. Punctuality is not always crucial in Spain. It’s also normal to take a 'siesta' or nap during the mid-afternoon. Remember to respect local traditions, especially during festivals.