Solo backpacking trip across SEA

I am 18 years old and a male from canada, i’ve been wanting to experience different cultures and just a different way of life so i bought a ticket to thailand in january. This is my first time out of North America. i am looking to meet new people and learn about cultures, and this is just my first trip so any tips will help.

I have no return date but i do have a general itinerary. start in Thailand, go down the islands then the north of Thailand, then into Laos then Vietnam. I want to go to Cambodia possibly but i haven’t heard great things for backpackers online. i also want to go to the Philippines and Indonesia and then hopefully end the trip in Singapore or maybe not i don’t really know

I have no time limit and i plan to have a budget of 1.5k per month but don’t want to be spending more than 1k(just have the other money as a cushion). is this a reasonable budget? obviously i’ll spending more in one country over another but yeah.

If anyone has any tips or anything for what to bring, type of backpack, documents to make sure i have as a canadian citizen, must see places, anything will help thank you !