It is a very easy campaign. You will start with strong army and vast territory (in Europe and New World). In addition you have a very powerful ally – Spain. They will take care of your south and north boarder. Moreover French fleet is one of the best. You can use all of your strong sides at the very beginning. Remember to develop navy – you will need it to transport you troops to distant territories.
Guidelines for territorial expansion
1. You have one army and one fleet on the south. Take them to Corsica and start war with Genoa. After you will conquer the island defeat Genoa and send their troops (supported with 1 or 2 regiments of Régiments Étrangeres) to the Savoy.
2. At the same time build some better infrastructure in Quebec and Montreal. Start to train Colonial Line Infantry and some Indian Musketeers. Try to conquer a whole Iroquois Confederation land with them.
3. After Iroquois attack Cherokees. There is not many of them so you would be able to defeat them very quickly. If you have a possibility you can transport here some army from Genoa, Savoy or Württemberg. When you defeat Cherokees, Louisiana should join you. It will grant you some money from taxes. It id a very nice region – people are very happy and satisfied. You do not have to keep any army there. Anyone shouldn't attack you here too.
4. Look how many troops Britons have at the east cost of North America. It will be easy to conquer their regions for the army that have defeated Indians earlier. Take all of their provinces and then propose peace treaty. They should accept it.
5. When you will have all British regions in the North America then you should take care of the lands that are very important in this campaign. You do not need to have many troops in America – you should better start to organize some army in Europe. Prepare your troops and send them (by ships – but beware of beberian sailors) to Egypt. When you will have the Cairo then try to sign a peace treaty with the Ottoman Empire (negotiate it). If they won't accept it, destroy their fleets on the Mediterranean Sea or conquer Jerusalem.
6. Leeward Islands are in the pirates hands. It should be easy to you to defeat them. Send there 6 or 7 regiments of line infantry. Note that, after the war pirates will try to revenge. They will attack your trade ships so prepare a strong fleet to cope with them.
7. Move your troops from Cairo to India (your opponents will have a strong army there so try to reinforce your regiments in France). Conquer Orissa and then prepare to enter Karnatik (you can try to take Calcutta if you have a while).It is good to train here some Colonial Infantry – it will better than line troops from Europe or North America.
8. Try to take Flanders in a very peaceful and diplomatic way (the is no sense in attacking your ally – Spain). You can give them Newfoundland, Windward islands and some unnecessary provinces from India. You can add some interesting technology too.
After defeating Iroquois and Cherokees, Louisiana should join you. It is a very valuable province because you will receive loads of money from there. In addition, you don't need to keep there any troops- people are so happy that they won't cause any problems in the future.
Spain will propose to exchange some territories with you. You can agree if you will be able to give away Flanders for any piece of land. It is also possible that Marat Confederation will want to make the same proposition. It is a good idea – it will be very important to have some areas near India to start the invasion.
Try to trade with as many countries as you can (sometimes you will have to pay a lot of money to set the route). Send Indiamans to the east and west cost of Africa – you gain a lot of money there. Moreover, when you will conquer Corsica you can try to send few corsair ship to the Aegean Sea.