Greetings, I am from China, Wechat Pay and Alipay is so normal here. Just few simple steps to set it up. Although, there are two versions of Wechat, one is you download the app in Mainland China, Hong Kong, Macao or Taiwan, the other version is outside of this places, it seems it is not possible to use Wechat Pay from the latter version.
Since 2018, Wechat Pay supports several overseas credit cards, including JCB, VISA and Mastercard, even you can add a Foreign Credit Card to Wechat Pay, it can be used in Wechat Wallet's merchants and cooperatvie brands in e-commerce, O2O, Didi, Air China etc. can't be used for general transfer and sending red envelopes.
Having Wechat Pay is super convenience while you travling in China, save you time and hassle. My suggestion is try to add the credit card to your accout. If it does't work, have freinds to send you money to your Wechat Wallet. The last option is find other exchange serivce. Anyway, the first step you need to do is to activate the Wechat Wallet.