I read part of the series in 2005, a young man was the protagonist, he was traveling to different worlds. I think he was telepathic and the most identifying thing I can remember was he had a flying snake or asp as a pet which possibly was his protector? He was in danger for some reason. Also there was a romantic interest female. The books were very distinct from one another. The second or third book he visited a planet that was extremely bio-diverse, where he was on top of all this vegetation and he realized how many layers of vegetation he would have to get to before he got to the ground and it was vast. I never finished it and it's been driving me nuts.
You're referring to the Pip and Flinx series by Alan Dean Foster.
The titular protagonist was telepathic, they traveled to alternate worlds, his companion was a 'minidrag' (basically a flying snake) that could spit venom and there was frequently a female love interest.
The 7th in the series ("Mid-Flinx") seems to fit your description of the heavily vegetated planet:
“What are our landing prospects in this vicinity?”
“The local vegetation rises to heights in excess of seven hundred meters, sir. There is some question as to the stability of the actual surface, even if it could be reached.”
“So there’s nothing?”
“I have noted the presence of a very few relatively growth-free mountain peaks which rise above the surrounding greenery. These exposed barrens may owe their existence to altitude, the absence of suitable soils, or a combination of factors. There are none next to the anomaly, but one is relatively close.”