You will still be able to enter charitable donations in 2018. It will just be a lot harder to get any deduction for them, since your standard deduction will be much higher. Itemized deductions only affect your tax due or refund if you exceed your standard deduction.
https://turbotax.intuit.com/tax-tips/irs-tax-return/2017-tax-reform-legislation-what-you-should-know...