If the Tzibur is saying lamnatzeach mizmor ldovid at the end of shachris, and I fell behind and am still in the middle of or didn’t start yet ashrei (either I just finished shmone esreh and didn’t start tachanun, or I’m in the middle of Tachanun, or I just finished Tachanun), should I skip to what ever the tzibur is up to and after davening say what ever I missed, or would it be better not skip and say the tefillah in order?
Also,if the tzibur is saying alenu and I’m in the middle of, or right before uva litzion (just finished lamnatzieach mizmor ldovid by shachris), is it better to join the tzibur and say alenu (and say uva litzion after davening?
Also , should I skip tachanun and/or ashrei after shmone esreh by shachris to say uva lzion together with the tzibur (and if the answer is yes, I should skip, should I say the whole uva lzion with them even after the kedusha part, and what about finishing the davening with them once I’ve already disturbed seder hatefillah)?
These questions aren’t just theoretical, because they happen frequently to me and I want to daven according to halacha?
The general rules are the following:
1. The first paragraph of Tachanun should be said right after Shemoneh Esrei, with as little interruption as possible.
2. The Kedusha parts of Uva Le’Tzion should be said together with the congregation, even at the expense of interrupting Tachanun or Ashrei. The other parts of Uva Le’Tzion can be made up later (Mishnah Berurah 132:3).
3. Aleinu should be said with the congregation, even if this means putting off Ashrei and Uva Le’Tzion for later (ruling of Rav Shlomo Zalman Auerbach zt”l). If you just finished Shemoneh Esrei you should finish the fist paragraph of Tachanun first and then join the congregation in reciting Aleinu.