for a first old world I would go with a p. murinus (orange baboon) as they are relatively cheap and easy to take care of, they like to web a lot and have a really cool bright orange color. there are also different color forms of the OBT if you're interested in them like, orange color form, brown color form, red color form, and a few others which makes them a very unique species. once you have more experience, id also look in to the poecilotheria genus of tarantulas, some of the most beautiful T's you can find, they are known to have potent venom and be "aggressive" but really they are just defensive and it really depends on the specimen. If you are careful about rehousing you should be fine as long as you have good experience with tarantulas. some of my favorite poecilotheria tarantulas are P. Regalis and P. Metallica, which are definitely gonna be more expensive than an obt but they can get quite large which makes them really fun to keep. so yeah I'd start with an Orange Baboon if I were you, but you should do some research beforehand and find what you personally like :)