There are a lot of different platforms to try and raise capital. You can try and borrow money from a traditional bank, or if you are in the US, the small business administration (SBA) has many programs to loan funds to small businesses.

Other startups try to raise money by issuing debt or equity to investors. Crowdfunding has also become a popular method of raising funds. The crowdfunding platform generally entails people "gifting" you money to fund your company, so any proceeds are generally treated as taxable income.