It sounds like your cat is getting to know you and is slowly developing a trusting relationship! He's in a new place with lots of new smells and things to explore, so it may take a few weeks before he feels "normal" and comfortable in your space.
As for the pacing - this sounds like normal curious cat behavior when they're starting to accept you. You'll know you're accepted if he rubs against you. Please note if a cat is walking in circles but seems to be stumbling or disoriented, this is very different and it needs to be brought to a vet
The paws on the leg sound like a friendly hi and perhaps a request for something. He could be asking to be petted, or needs food/water, or wants a treat.
Reward any trust behavior with treats, and talk to him in a soothing tone. Try to move slower when you're around him, and don't make sudden moves or noises. You could try coaxing him to play if you've got any toys. Playing is a great bonding activity. Good luck! It sounds like you're on your way to having a new best friend!