Need help to understand how to do Revenue and Cost projections based on historical data, based on Time Series Model. Hopefully the most basic and easiest way to do it.

Below is the historical data for the company:

Revenue of Merchandise Sales
2015	25,623,744,195
2016	32,223,375,519
2017	36,644,463,348
2018	43,770,478,130
2019	52,950,902,607
2020	43,645,923,273
2021	45,144,606,258
Q1 2021	10,522,406,387
Q1 2022	12,770,823,625
2022	?????
2023	?????
2024	?????
2025	?????
2026	?????

Cost of Merchandise Sales
2015	16,891,590,340
2016	21,361,119,960
2017	23,776,474,291
2018	27,911,183,499
2019	34,368,460,873
2020	28,783,351,394
2021	29,656,633,373
Q1 2021	6,939,518,570
Q1 2022	8,513,755,086
2022	?????
2023	?????
2024	?????
2025	?????
2026	?????

Please show computations to better understand as I have no background in accounting.