You often need to convert text to Affinity Designer curves to access the nodes. Select the artistic text tool (or the frame) in the toolbar. Click document art board at the location you want to add your letters etc. Select the required font from the font list. Select the size and color. Add something (one character or more) to the art board
You can right click the artistic characters OR Go to the layer menu and use the convert to curves command there OR Use the button along the far right of the context toolbar. There are probably a few more tucked away in other parts of the application.
Select the command mentioned above and all the characters will now become normal paths and the entire word etc will be part of a group. Once you have run the command the characters / words are not live and cannot be edited using the usual tools but having access to the nodes gives even more creative possibilities
Goto the layers panel (found in the view and studio and layers) or double click the individual character in the document and select the character so if you changed 'XYZ' you will see a group made up of 'X' 'Y' 'Z'. Select the node tool / move tool and select the character you want to work on via the layers panel. The same can be done with the frame.
If you wish to manipulate the nodes of the individual characters from your design, use the move tool. With the move tool you can then manipulate the size, angle, fill, stroke etc of the individual characters but you cannot modify the overall shape or the points / nodes of the paths.
If you want to manipulate the individual characters and tweak the nodes / points then select the node tool. You can then drag the points in all kinds of directions to create weird and wonderful designs from your art.
The layers panel is super useful in changing the blending modes and opacity of the individual characters. Set them to all kinds of blends such as darken or difference etc
You can change the letters into normal paths and then combine the art with another path such as an ellipse or cog design etc
Select the artistic tool (as above) and select font / size etc and click document / art board and create design via keyboard character. Right click and select the conversion command / button. Go to the ellipse tool. Create an ellipse. Select both designs. Use one of the combine / subtract etc options found via the top bar / control bar of the application or layer menu geometry commands.
If you add multiple shapes on top of your design it is tempting to thing you can simply use the geometry command and remove those paths from the underlying characters, the result will be yes, the shapes are removed but all but one of the entries will also be removed. If you want to remove spots or lines or parts of multiple paths then you have to do it individually so select (move tool) the shapes on top of the letter 'T' as well as the letter and then apply the layer menu geometry command and then go to the 'E' (or whatever character) and select the shapes above that along with the letter and again use the layer menu and geometry etc. It should be noted that the additional designs should be above the letters otherwise the letters will chop away from the shapes. Not the quickest approach.
One of the more interesting options in the geometry has to be the divide as that splits the paths into individual components. Create your characters and apply the command / button and then create some shapes on top of the current letters. The divide has no issues with all the characters and shapes selected, it will divide everything. So what happen ? Go to layer menu and geometry and divide and you will get paths where the paths intersect so instead of 8 shapes and 4 characters, you will potentially end up with 20 or 30 individual paths and those paths can then be manipulated as new lines. To select the individual lines, double click the paths or use the layers panel to select the individual parts and then you can break your characters and words apart even more. It should be noted that they all have to be part of the same group of changed words and lines to work with the divide.
Say you want to create a line cutting design from your characters using lines, all the lines and the expanded character designs need to be part of the same group before you run the geometry command. You can then use the move tool (double click the individual paths or use the layers panel) and move the any of the paths
You can always remove the lines if they are a different color from the expanded characters, select one of the lines (the red etc) and then go to the select menu and select same and fill color and then delete all the lines in one go or shift them around
You can expand some characters by the above mentioned method and then duplicate the design, apply a slight shift and then use the layers panel to select both sets of the same characters and then right click and use the geometry command and subtract command. A quick emboss. Sadly, you cannot do it by the group but it has to be done on each character in turn and it is not live
Once your letters have been changed into normal paths, you can apply the corner tool to round the characters. Some of the characters are pretty round already and will not be changed by the corner tool but it will work for K and T etc. Expand the characters but you have to go to the layers panel and select the individual characters and then use the corner tool on each and you can only round to maximum allowed for the character