We can use WP native gallery shortcode to align two images side by side.
WP native gallery
https://codex.wordpress.org/The_WordPress_Gallery
Gallery Shortcode
http://codex.wordpress.org/Gallery_Shortcode
On a side note, please consider not using inline style for every <p> like <p align="center">. Just write normally and WP will automatically wrap block of text into <p> tag and we can control its style in stylesheet.
Also, avoid hotlink image one by one from flickr. What would happen if flickr change url pattern? hundred or thousand of images in the blog will be missing.
Upload images to WP via post editor will attach image to that particular post, so we can manage images for that post. For post that has lots of images, pick like 5 or 10 best shots to use in the post and then make a text link to the album in flickr.
How to use image in post
https://codex.wordpress.org/Inserting_Images_into_Posts_and_Pages
Hi!
Thanks for getting back so fast – it’s a bit complicated – I’ve been using Flickr to store my photos and linked back from the posts since 2009 and want to continue doing so (they haven’t changed their url pattern and I would be surprised if they did) since this doesn’t affect my storage space and I have all my photos (11thousand) in one place. Uploading photos to both flickr & wordpress won’t be an option since I’m too often in places with ridiculous bandwidth.
How many photos I choose to post on each post is really not relevant. What I want to know is why if I make the photos 390px it’s all right, but 400 each won’t fit next to each other – even though ONE photo of 800px is no problem. Where can I adjust this post width limitation since many hundreds of previous posts have this set up?
Again – the question is not about addressing future posts and giving me alternative options to how to upload photos – it’s about making sure all my old posts display correctly.
(I really don’t like the WP gallery, sorry, it still has a loooong way to go before it gains my trust)