You can value it how you want, however an investor has to agree with your valuation. If you have ever watched the tv show Shark Tank - a very high valuation is a quick way to END the investor conversation.
The revenue / EBITDA multiplier is typically based on your "revenue growth". Startups growing revenue 2-5x a year have a higher multiple than a startup growing revenues 40% a year. There a lot of factors that go into the calculation and each investor will have a slightly different formula they use.
If you have only been around 2 months or have little to no revenue, revenue multiples don't work. I would start with a conversation with the closest business accelerator or business professors in your local area.
Tech startups typically have higher multiples as well.