This is great English. I don't see anything wrong with it from a syntactic point of view, so I'd say it's perfect English. But it doesn't feel like it's conveying the right concept, logically.

When you say "<X is true>, but <Y is true>" that usually implies that fact Y in some way contradicts or goes against fact X. For example, "I want to be a basketball star, but I'm not very tall". The implication is that not being very tall is somehow inconsistent with becoming a basketball star. Which is true. So that's a proper use of "but".

Your "I am a beginner, but I am interested in hiking" implies that being interested in hiking is inconsistent with being a beginner hiker. But the reverse is true, if anything. People, as a rule, are MORE interested in an activity or hobby earlier on than later on.

Since you got your English perfectly correct, I would encourage you to try another few sentences that say how you feel about hiking, how good you are at it, how easy/difficult you find it, how long you've been doing it, and what kinds of hikes or scenery you like. But really think about the meaning as well as the syntax.

Hiking

Hiking

Everything looks good[emoji]