The only way to add non-live videos to your profile is to have Twitch record your past broadcasts, you cannot upload your own videos.
For all intents and purposes, yes, you’ll need a PayPal account if you wish to have people donate.
Otherwise, you’ll need to get partnered to make money, which generally requires a minimum of 200 average viewers and several streams per week to achieve (or joining a streaming group, but if you don’t have enough viewers to get partnered on your own, it’s unlikely that you’ll get enough subs to make any money off it anyway).
If you wish to start streaming, do so without the intent of making money. The people with the most success (interesting content and enough viewers to make money) are usually the ones who stream because they want to share their content with others. It may be a long road to get to that point, and if you don’t have the desire to keep streaming on your own (even if you’re not profiting from it), you might not last long enough to ever even get there.