I am building a PC without optical drives. Will I be able run Ubuntu from an USB flash drive?
My plan is to try out Ubuntu on my built PC using USB flash drive and then depending on how I much like Ubuntu; either installing Windows 10 onto my SSD with Ubuntu alongside/inside it, or just installing Ubuntu onto my SSD without Windows. Will my plan be easily possible?
You can do a Full install to the flash drive. Most computers see a flash drive as just another hard drive.
A Full install will probably give you a better feel that running a Live or Persistent system.
If your new computer has lots of RAM, Ubuntu will run in the RAM, so there should not be issues with speed.
A Full install requires a larger flash drive than a persistent install, about 8GB minimum.
Follow OldFred's advice when it comes to UEFI.
