- For it to be GPLv2, I need provide access to my source files?
No, you don't. You are not bound by the terms of the license. The purpose of a license is to give you rights that you wouldn't otherwise have … but as the copyright holder and / or author, you have all rights anyway. Therefore, you don't have to provide the source code.
BUT! It would not make sense.
Presumably, you chose the GPLv2 for a reason. But without access to the source, the recipients of your license cannot do what the GPLv2 allows them to do. So, you don't legally need to provide the source code, but practically it doesn't make sense to release software under the GPLv2 without source code.
- If I use the v2 license, but charge for use, do users HAVE to purchase my license in order to use it?
No. Only the first one. All the other ones could theoretically get the software from the first one, who can legally re-distribute it under the terms of the GPLv2.
However, there is nothing that guarantees that the first user will actually re-distribute it. The GPLv2 allows it, it doesn't force it.
- What is the alternative license in creating software if I want to charge for it?
Actually, it is perfectly possible to charge money and make profit off GPLv2-licensed software:
- Just because the GPLv2 allows your users to re-distribute the software doesn't mean they will.
- Some (corporate) users want to pay for software, or actually, they want to pay for the possibility of having a contract with someone that they can sue if the software turns out to hurt their business in some way.
- You don't sell the software, you sell support and services related to the software. Maybe you give training on how to efficiently use the software, maybe you give extended support contracts, maybe you sell bespoke feature development.
- A lot of high-profile projects have an "open core" model, where the core and basic functionality is open source, but the real value of the product is in extensions and plugins, some of which are commercial and proprietary.