I have been stuck in situations where I don't have Photoshop or any other photo editing program installed on some of the work computers when I have some photos that either need to be converted or need some editing done. There are so many resources available now to manage not having to download the major photo editing software.
Everyone loves a little Canva! Canva is very useful to crop and resize photos, along with making minor and basic tweaks to the lighting and overall look of the photo. You can also use filters to make the photo fit the coloring or style you're trying to achieve. If you want to turn your photo into a card or overlay text onto it, this is a great tool with an array of presets and templates.
Have you ever received a file that needs to be converted for you to actually see what it is or use it in a blog post or website? There are a lot of different converters that will help change files from what they are originally to what you need them to be. I had an SVG file that I needed to be changed into a PNG. So I used CloudConverter. This was very useful and helped me get the file I wanted to use in other areas of my editing.
This is a great tool if you want to get creative with your photos without having to know the ins and outs of Photoshop. You can pay for some of the features or see what the free options are much like Canva.
If you do have Photoshop experience but just can't download Photoshop on your work computer or other computers you're using to edit, PhotoPea has the same functions as Photoshop and a lot of the same keyboard shortcuts. Use this to resize, touchup and do full editing to your photos.
Fotor is a great editor which helps you put more graphic design into your photos. There are a lot of different options with this application and has great options to choose from.
I hope this helps get you out of a rut when you stuck without Photoshop. These tools have bailed me out in a hurry as I have worked on projects as a digital marketer where the company had a design department where they weren't willing to put Photoshop on everyone's computers. So as I had quick edits to make on photos. to able me to continue working on social media posts or blogs, I have use these to make the edits I needed to not waist time and money.