I forgot to include another w2, ones for the past year and one for this year, can I include this two one for 2018 and one for 20019 in my next year of tax preparation? P

The 2018 W-2's can Only be entered on a 2018 tax return.

The 2019 W-2 Must be entered on the 2019 tax return.

If you have e-filed your tax return and need to change, add or delete information on the tax return then you will need to wait for the tax return to either be accepted or rejected by the IRS.
If the tax return is rejected then you can make your changes and re-file the tax return.
If the tax return is accepted then you will have to amend the tax return to make your changes. An amended tax, Form 1040X, return can only be printed, signed, dated and mailed by you to the IRS, it cannot be e-filed. The IRS will take up to 4 months to process the amended tax return. Wait until you have received the tax refund or the taxes owed have been paid and processed by the IRS before amending the tax return.

See this TurboTax support FAQ for amending a 2018 tax return - https://ttlc.intuit.com/community/amending/help/how-do-i-amend-a-return-in-turbotax/01/27579