There is a lot of free stuff on youtube. I have learned plenty from it. Also, if you have paid subscriptions, there is plenty of Yoga classes on Netflix, Amazon Prime, and The Gaia channel.
Many studios are really posh and expensive. If you go the fiances for it, totally go for it. Some poses can be dangerous and it helps if someone shows you a correct way to position yourself so you wont injure yourself. Lots of gyms offer basic Yoga classes with entire membership, that is a good bang for your buck option.