I am new to database work.  I need two simple forms

1.  Apartment Form - with a "tenant apartment number"  and a  "tenant phone" feild only.

2. Repair Form -   with an input feild "tenant apartment nunber",  a "repair needed" feild and a "repair telephone" feild

After all tenents are entered in the Apartment Form database,  I would that on the Repair Form I could just enter an apartment number (not a dropdown, but enter it via keyboard) and the tenants telephone shows automatically in the "repair telephone" feild.

I am confused with this proceedure.  Can I ask for help with a step by step proceedure to accomplish this?

Thank you