Deciding on a bag for one month in Asia

I’ll be spending two weeks in Thailand and two in Japan in May and I am having a tough time deciding on a bag. I’ve never backpacked before so I don’t have a great idea on what I’ll appreciate in a bag. Will be bouncing from city to city staying in hostels and taking atleast 6 flights while I’m there. From what I’ve read/watched on YouTube I’ve narrowed my search to bags with a capacity between 35-40 L around the $300 ish CAD. I won’t be packing any laptops or camera equipment, mainly just clothes and toiletries. Im currently looking at the Cotopaxi Allpa 35-42L or an Osprey Farpoint. Was hoping you guys would be able to steer me in the direction of the right bag, any other suggestions are welcome. Thanks!